Abstracts & Papers Read - Professor Tim Patterson, Ph.D

Abstracts and Papers Read

2026

24x. Roe, H.M., Hatton D., Patterson, R.T., Leavitt, P., McMullin, D., Walsh, C., McCann, E. Reinhardt, E.. 2026.

Untangling the drivers of shallow lake cyanobacteria blooms in the Canadian Maritimes: insights from palaeolimnology. QRA Annual Discussion Meeting 2026, University of Brighton, United Kingdom, Session 5: Environmental Change. 7 January 2026, p, 9, 64.

Read the Abstract - Abstract 24x

The global increase in the frequency and intensity of cyanobacteria blooms has been widely attributed to changes in land-use practices and climate variability, yet little is known of how lake toxicity has varied historically relative to cyanobacteria population abundance. This study analysed dated (210Pb;137Cs) sediment cores from three lakes in southwestern New Brunswick, Canada, a region which has recently experienced a rise in lake harmful cyanobacteria blooms (cyanoHABs). Multi-proxy sediment analyses (end-member modelling analysis of grain-size distributions (EMMA), ITRAX-XRF; stable isotopes: δC; δN), were used to explore links between the drivers of limnological change (e.g., climate variability, historic storms, land use change), and past episodes of CyanoHAB development. Cyanobacterial responses were investigated using taxonomically-specific sedimentary pigments, including aphanizophyll (N-fixing), echinenone (total cyanobacteria), canthaxanthin and myxoxanthophyll. Microcystin congeners LA, LR, [Dha7] LR and RR were quantified using high-resolution tandem mass spectrometry (HRMS/MS). Although decoupling the compounding drivers of lake cyanobacteria occurrence from sedimentary records is challenging, initial EMMA, and ITRAX-XRF derived ratios (Br+Cl/Al), which are linked to precipitation and air mass patterns, showed co-variance with increases in lake productivity. δN, which represents fossil nitrogen inputs, exhibited the strongest correlation with productivity proxies. This suggests that catchment-mediated processes such as agriculture and urbanisation, strongly influenced CyanoHAB development. A late 20th century increase in cyanobacteria concentrations is attributed to heightened nutrient inputs. This set the stage for significant cyanoHAB occurrences in 2015, likely attributable to lake fertilisation triggered by the passage of a major extra-tropical storm..

2025

2024

245. Roe, H.M., Patterson, R.T., Hatton, D.A., Walsh, C.M., Leavitt, P.R., McCann, E.T., McMullin, D.R., Reinhardt, E.G., 2024. Tropical Cyclones as AN Emergent Contributor to Development of Harmful Algal Blooms in Northeastern North America. Session: 214-10 – TROPICAL CYCLONES AS AN EMERGENT CONTRIBUTOR TO DEVELOPMENT OF HARMFUL ALGAL BLOOMS IN NORTHEASTERN NORTH AMERICA. Tuesday September 24, 4:10-4:25PM. Geological Society of America Connects Abstracts, Anaheim, California, USA, Vol. 56, p. 404784. doi: 10.1130/abs/2024AM-404784.

Read the Abstract - Abstract 245

Lake disturbances caused by extreme weather events (e.g. tropical cyclones (TC) can lead to post storm nutrient pulse events; derived from a combination of heavy rainfall related nutrient runoff from the catchment and large wave driven resuspension of lakebed nutrient-rich sediments. This can alter lake ecological conditions to favor cyanobacteria over other phytoplankton, and development of harmful cyanobacterial blooms (CyanoHABs). Although a mechanistic link between TC forcing and lake community shifts has been observed through in-situ monitoring, it has not yet been demonstrated in paleolimnological records.

In this study, we showcase sediment cores dated using 210Pb and 137Cs from two lakes (Harvey, Wheaton) in SW New Brunswick, Canada, a maritime region that has witnessed a recent rise in lake CyanoHABs. These cores have been analyzed to investigate connections between historical toxic bloom events and influencing factors. Multi-proxy sediment analyses (end member mixing analysis (EMMA) of grain-size distributions, ITRAX-XRF; stable isotopes: δ13C; δ15N) were employed to explore mechanistic links between drivers of lake change (e.g. climate variability, land use change, TC) and past episodes of CyanoHAB development. Cyanobacterial responses were investigated using taxonomically specific sedimentary pigments: aphanizophyll (N2-fixing), echinenone (total cyanobacteria), canthaxanthin and myxoxanthophyll. Microcystin congeners LA, LR, [Dha7] LR and RR were quantified using high-resolution tandem mass spectrometry (HRMS/MS).

Although decoupling the compounding drivers of lake cyanobacteria occurrence from sedimentary records is complex, initial EMMA, and ITRAX-XRF derived ratios (Br+Cl/Al) associated with precipitation and air masses displayed co-variance with productivity increases. However, δ15N, representing fossil nitrogen inputs, exhibited the most significant correlation with the productivity proxies, indicating that catchment mediated processes (e.g. agriculture, urbanization) had a strong influence on CyanoHAB development. A late 20th century increase in baseline cyanobacteria concentrations is attributed to heightened nutrient inputs. This set the stage for significant CyanoHAB occurrences in 2015, directly attributable to lake fertilization triggered by passage of post-tropical storm Arthur in 2014.

244. Roe, H.M., Macumber, A., Prentice, S., Patterson, R.T., Sayer, C., Emson, D. 2024. Exploring the Links between Testate Amoeba Traits and Eutrophication in Lakes. EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18509, https://doi.org/10.5194/egusphere-egu24-18509, 2024.

Read the Abstract - Abstract 244

There is considerable potential to apply traits-based approaches to the subfossil remains of shell-forming micro-organisms which preserve well in sediments and whose short generation times make it possible to achieve high-temporal resolution in palaeoecological studies. In this paper we review progress in applying traits-based approaches to freshwater testate amoebae (Arcellinida), a diverse group of protists which are abundant in lakes and are valuable palaeoecological indicators. Drawing on published studies from the last ~10 years, we describe the methodologies which have been applied to delimit testate amoeba (TA) traits and review the challenges associated with their measurement and interpretation. We also showcase the results of ongoing work in seven lakes (UK, Canada) which aims to (i) examine the character and causes of trait-based variability in palaeolimnological settings; (ii) apply novel biometric approaches to aid in trait delimitation; and (iii) explore the potential for combining phylogenetic with advanced morphometric approaches to better understand the ecological and evolutionary significance of TA traits.

We applied geometric morphometric analysis to define test size and shape indices and summarise testate amoeba community dynamics along a temporal gradient of eutrophication in a large shallow lake in Scotland, UK. Cluster analysis of test size and shape indices yielded three assemblages, each dominated by a single shape: elongate, spherical and ovoid. When plotted stratigraphically, we observed increases in spherical tests, decreases in elongate tests and shrinking of test size coeval with eutrophication. Decreases in the elongate cluster may reflect benthic conditions with reduced oxygen levels, while increases in the spherical cluster are likely associated with an expanding macrophyte community that promoted pelagic and epibiotic life habits. Shrinking of test size may be a stress response to eutrophication and/or warming temperatures. Tracking community dynamics using test size and shape indices was found to be as effective as using traditional species-based approaches to summarize key palaeolimnological changes, with the added benefit of being free of taxonomic bias. The approach thus shows significant potential for future studies of aquatic community change in nutrient-impacted lakes.

To further investigate the functional significance of the Arcellinida shape groups, we examined the phylogenetic signal of morphological traits in elongate Difflugia species which occur in eutrophic and mesotrophic lakes. Previous phylogenetic work has shown that whilst overall test morphology (e.g., spherical or elongate) is generally conserved in Arcellinida lineages, the taxonomic significance of other traits (e.g., size, ornamentation, mixotrophy/heterotrophy metabolism type) is not well understood. Our analyses revealed two clades which could be reliably separated by test size and the presence/absence of mixotrophy. This suggests that test size may reflect trophic level, with smaller taxa occupying lower trophic levels. In addition to having larger tests, elongate mixotrophic Difflugia are characterised by wide, flat bases and inflation of the lower part of the test. These morphological traits may provide additional space for endosymbionts and/or increased surface area to aid light transmission. Continued research into the ecological and evolutionary significance of morphological traits will serve to strengthen palaeoecological inferences, increasing the importance of lacustrine testate Arcellinida as environmental proxies.

243. Patterson, R. T., McCarthy, F. M., Head, M. J., Walsh, C. R., Riddick, N. L., Cumming, B. F., Hamilton, P. B., Pisaric, M. F., Gushulak, A. C., Leavitt, P. R., Lafond, K. M., Llew-Williams, B., Heyde, A., Pilkington, P. M., Moraal, J., Nasser, N. A., Garvie, M., Roberts, S., Rose, N. L., and Roe, H. M.: The varved sediment succession of Crawford Lake, Ontario, Canada: GSSP for the proposed Anthropocene Epoch , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13348, https://doi.org/10.5194/egusphere-egu24-13348, 2024.

Read the Abstract - Abstract 242

The Crawford Lake sedimentary sequence in Milton, Ontario, Canada, has been chosen as the Global Boundary Stratotype Section and Point (GSSP) for the proposed Anthropocene Series/Epoch, with its inception occurring at 1952 CE in the mid-20th century. This sequence consists of seasonally deposited layers of organic matter capped by summer-deposited calcite, forming in alkaline surface waters when pH and temperature rise above 7.76 and ~15°C, respectively. These sediments preserve a range of proxies that mirror environmental shifts spanning from local, to regional, global scale, indicative of the Anthropocene’s onset. Notably, a significant uptick in industrial fossil fuel combustion in the early 1950s is recorded by increased spheroidal carbonaceous particles and a shift in the sediment’s nitrogen isotope composition. During the 1960s, the ratios of 239Pu:240Pu and 14C:12C peak, aligning with heightened radioactive fallout from atmospheric nuclear weapons testing, counterbalancing the old carbon effect in Crawford Lake’s dolomitic basin. Post-World War II industrial growth in the Great Lakes region, part of the so-called Great Acceleration, led to acid rain that diminished calcite deposition and impacted primary productivity in the lake. This change is reflected in thinner calcite layers concurrent with the proposed GSSP. These varve thickness variations correlate with climate patterns and lake productivity trends, influenced by cycles like the Quasi-biennial Oscillation, El Nino-Southern Oscillation, the 11-year Schwabe sunspot cycle, and the Pacific Decadal Oscillation. The absence of pigments from anaerobic purple sulfur bacteria suggested an oxygen-rich monimolimnion but with elevated bottom-water salinities that was subsequently confirmed by water property data collected through the modern lake water column in all seasons. Such an aerobic depositional environment is highly atypical for a meromictic lake and it was the elevated alkalinity and higher salinity conditions that resulted in preservation of varves. The oxygenated bottom waters serendipitously prevented the mobilization of 239Pu in the lake sediments, a key primary stratigraphic marker for the Anthropocene.

242. Hatton, D.A., Roe, H.M., Patterson, R.T., Nguyen, A.V., Walsh, C.R., Kumar, A. 2024. Resolving significant offsets between AMS 14C and 210Pb chronologies in palaeolimnology: applications of Spheroidal Carbonaceous Particles (SCP) Analysis and historic pollen markers. Quaternary Research Association Annual Discussion Meeting, Manchester, UK, 4-7 Jan 2024.

Read the Abstract - Abstract 242

The development of robust sediment core chronologies is critical to understanding the depositional history of lake sedimentary archives. This is especially important when the primary focus is on establishing the rates or timing of limnological changes, or when instrumental observations are used in parallel to validate proxy data. AMS radiocarbon and 210Pb dating are amongst the most common techniques applied in palaeolimnology. However, the selection of dating technique is often influenced by the available sediment, budgetary constraints and project timeframes. The presence of terrestrial plant remains and other suitable material for AMS 14C dating (e.g. pollen) further influences the selected dating approach. When these are not available, bulk sediment AMS 14C dates (representing multiple autochthonous and allochthonous carbon sources) are extensively used to develop chronologies.

Here we describe chronologies developed for two shallow lake cores from New Brunswick, Canada (Wheaton and Harvey lakes) based on 210Pb, 137Cs, and AMS 14C bulk dating. These cores were collected as part of an ongoing palaeotempestological study which is examining the impact of extreme weather events on historic cyanobacteria blooms. The radiocarbon ages for both lakes are internally consistent and indicate a slow mean core sediment accumulation rate (ca. 6 yr/mm). However, PLUM-derived (R Software) age-depth models developed from the 210Pb data suggest a much higher mean core sediment accumulation rate (<1 yr/mm). The respective pairs of models show an age offset of between ca. 500 – 1500 years for the two dating techniques. These findings are not unique as other studies have reported similar discrepancies. These issues clearly present difficulties when interpreting palaeolimnological records and raise questions in relation to optimal practice for the development of age-depth models from lake sediments, especially when dating resources (or suitable material) are limited.

To reconcile the significantly different results obtained using the two dating methods, we examined Spheroidal Carbonaceous Particles (SCPs) and historical pollen ‘markers’ from the two cores. In both cases, the results suggest that the 210Pb age-depth models more accurately reflect the depositional history of the lakes. Like other records in the region, both cores yielded a ‘typical’ SCP profile, with an early ‘expansion’ phase, a ‘peak’ and a subsequent decline. Whilst the magnitude of these established SCP concentration phases varies spatially and temporally throughout the region, the inferred age of the peak concentration in the mid-twentieth century (as suggested by the 210Pb models) is more consistent with other dated core records from the region and the history of industrial expansion. Furthermore, the onset of the rise in ragweed pollen (e.g. Ambrosia), an established regional marker which can be linked with land clearance associated with European settlement, further aligns with the extrapolated 210Pb age-depth models produced for each lake site.

This research highlights the benefits of supplementing radiometric dating with ‘time-equivalence’ dating approaches to refine chronologies developed for lake sediment cores. It also suggests that bulk radiocarbon dates from lake sediment cores should be interpreted with caution, even in places where there are no known carbonates or other sources of ‘old carbon’.

2023

241. Walsh, C.R., Hatton, D.A., Patterson, R.T., Nasser, N.A., Reinhardt, E.G., Patterson, C.W., Gregory, B.R.B., Mazzella, V., Roe, H.M., Galloway, J.M. 2023. Detecting Tropical Cyclone Activity in inland Lake Sediments from New Brunswick, Canada. IGCP Project 725: Forecasting Coastal Change, Florianopolis, Brazil, 21-27 Oct 2023.

Read the Abstract - Abstract 241

Major Tropical Cyclone (TC) events each year cause extensive damage in coastal regions throughout the Western North Atlantic Basin. The short instrumental record significantly limits the understanding of long-term trends in TC recurrence and intensity, creating uncertainty for modeled projections of future storm trends. Sediment cores taken from Harvey Lake and Wheaton Lake, located within 80 km of the Atlantic coast in southwestern New Brunswick, Canada were subsampled at high resolution and analyzed using end-member mixing analysis (EMMA) of lake sediment grain size distributions and ITRAX X-ray fluorescence (XRF). Using EMMA, sedimentological processes related to TCs, spring runoff, and heavy precipitation events were identified. ITRAX derived elements/elemental ratios (Fe, Ti, Ca/Sr, Zr/Rb, K/Rb, and Br + Cl/Al) associated with changes in precipitation patterns, weathering, catchment runoff, and infiltration of marine air masses were used to assess temporal changes in catchment dynamics related to longer scale climatic changes. Together the EMMA and ITRAX data were used to carry out CONISS stratigraphic clustering for each core, resulting in temporal zonations indicative of reduced TC activity during the mid to late Little Ice Age and a resurgence of both TC and major rainfall events during the modern warm era. We demonstrate that the use of EMMA provides a robust tool for recognition of TC and major rainfall events, and greatly expands the potential for paleo-storm activity research well inland from coastal regions.

240. Walsh, C.R., Ralchenko, M., Patterson, R.T. 2023. Influence of the tempo and mode of cyclic climate drivers on tropical cyclone intensity, and centers of action, in the Western North Atlantic basin. IGCP Project 725: Forecasting Coastal Change, Florianopolis, Brazil, 21-27 Oct 2023.

Read the Abstract - Abstract 240

We previously used an instrumental tropical cyclone (TC) intensity time series to analyze and interpret grain size data from core records for the presence of TC deposits. This time series was derived by scaling maximum wind speeds within a search radius of interest. By calculating Pearson’s correlation coefficient between the instrumental TC time series and the time series representing the abundance of specific sediment groups when both time series overlapped, we rigorously established a relationship between sedimentary processes and TC events. The grain size-derived time series had clear periodic components, and modern TCs have broadly been linked to the fluctuations in large-scale climate oscillations. In this study, we tested the relationship between several large-scale climate oscillations and TC intensity across the Atlantic Basin (AB). The time series correlation approach was scaled up to calculate a comparable intensity time series for every point within the AB at 0.1^o latitude by 0.1^o longitude resolution (latitude range 0^o–70^oN, longitude range 0^o–110^oW). Next, Pearson’s correlation coefficient was then calculated at each point between the TC intensity time series and the time series for various known climatic drivers. This exercise generated geographic maps of regions where a given driver (e.g. Atlantic Multidecadal Oscillation (AMO), El-Niño Southern Oscillation (ENSO), North Atlantic Oscillation (NAO)) has been determined to have a greater or lesser correlation to TC activity, along with contours of statistically significant portions (above the 95% confidence level). This work is computationally demanding; the instrumental data set has over 50,000 rows, and with the geographic resolution used, approximately 40 billion observations were processed for each tested climatic driver. To make this analysis tractable, the calculations were done with a highly optimized code which ran on a graphics processing unit (GPU). Within the AB, most climatic drivers were generally observed to have geographically discontinuous regions where correlations were statistically significant, except the Atlantic Multidecadal Oscillation (AMO), which yielded statistically significant positive correlations in a large portion of the study area, including much of coastal North and Central America. Furthermore, examination of these maps resulted in the formulation of a series of testable hypotheses for future paleotempestology work. As suggested by the analysis of modern instrumental data, are certain periodic climate patterns observable at a variety of locations in the Atlantic basin? In what way do interacting independent climatic drivers influence TC intensity? For example, due to the widespread correlation with the AMO, these results suggest that a 50–90 year periodicity should be observable in paleotempest records throughout most of the basin.

239. Ralchenko, M., Walsh, C.R., Patterson, R.T., Patterson, C.W., Singer, D., Reinhardt, E.G. 2023. Trends and cycles in 4,000-year paleolimnological records of tropical cyclone activity from San Salvador Island, Bahamas. IGCP Project 725: Forecasting Coastal Change, Florianopolis, Brazil, 21-27 Oct 2023.

Read the Abstract - Abstract 239

Two sediment cores from adjacent Crescent Pond and Moon Rock Pond on San Salvador Island (SSI) in the Bahamas were analyzed to assess long-term tropical cyclone (TC) behaviour in the region. An approximately 4,000-year-long record was obtained for each of these cores, which were sampled at millimetre scale providing a subdecadal temporal resolution. Following grain size analysis, end-member mixing analysis (EMMA) was carried out to identify TC-related end-members (EMs). Historical instrumental TC data (1851‑present) was statistically correlated to portions of the cores that correspond to the historical record. This approach rigorously determined that a distinctive EM with the same modal grain size was present in cores from both ponds, and that this EM we emplaced by TC activity. Time series analysis of these TC records was carried out to assess long-term and cyclical trends in TC activity. Through comparison with time series analysis results of the modern instrumental record at SSI, the paleo TC activity observed from the cores was determined to be associated with several interdecadal climatic drivers, including the Atlantic Multidecadal Oscillation (AMO), the Pacific Decadal Oscillation (PDO), and the North Atlantic Oscillation (NAO). A cyclicity of 1,300 years was also observed in the TC EM time series, which elsewhere in the Western North Atlantic Basin (WNAB) has been associated with alternating cool and warm periods through the Holocene. Two major periods of high TC activity were identified in these core records; a hyperactive period was observed between ∼800 BC and ∼1100 AD, and a secondary active period was observed from ∼1300 AD to ∼1800 AD. Paradoxically, cooler climatic conditions in the WNAB were associated with increases in TC activity, whereas warmer conditions were associated with decreases in activity. These variations in TC activity recorded on SSI were possibly due to storm track changes that occurred as a result of movement in the position of the Intertropical Convergence Zone (ITCZ), or alternatively due to surface sea temperature anomalies.

238. Nguyen, A.V., Galloway, J.M., Patterson, R.T., 2023. Potential effects of sulfur-rich fumigation on testate amoebae assemblages, Smoking Hills area, Northwest Territories, Canada. Session 3: Bioindication. Tuesday, 3 October. 10th International Symposium on Testate Amoebae (ISTA 10). Madrid, Spain, 2-6 October 2023.

Read the Abstract - Abstract 238

The Smoking Hills (Ingniryuat), in the Horton River area of the western Canadian Arctic is characterized by areas of spontaneously combusting bedrock of the Upper Cretaceous Smoking Hills Formation. Active bocannes expel vapors that contain dark carbonaceous aerosol and trace gases with significant SO2 and H2SO4, which are very similar to anthropogenic industrial pollutants in chemical makeup. While the smoke from the bocannes is a minor contributor to overall Arctic air pollution, their effect at the regional and local scale could be significant. The long duration of the fumigation, with some estimated to have been active for at least 10,000 years, has introduced geochemical anomalies in the nearby soils. This has resulted in elevated acidic conditions and a high relative enrichment of trace metals in soils in the area of fumigating sites.

While there have been only limited studies on the direct impact of sulfur contamination on testate amoebae (TA), studies have shown that TA assemblages are sensitive to sulfate. In these studies, there was a notable significant decrease in small bacterivorous taxa such as Trinema lineare, Corythion dubium, and Euglypha rotunda in comparison to TA species that have less specific feeding preferences. Comparing TA assemblages using multivariate statistical techniques, including partial correspondence analysis, between actively fumigating peatlands vs non-fumigating peatlands in the Smoking Hills area are being assessed to determine if/how fumigation and/or bedrock composition impacts TA assemblage structure.

237. Hatton, D.A., Roe, H., Patterson, R.T., Leavitt, P.R., Reinhardt, E.G., McCann, E.T., McMullin, D.R., Nasser, N.A., Marshall, M.G. 2023. Understanding the role of palaeoclimatic drivers on cyanobacteria bloom development in shallow lakes. Session 28: Timing and structure of freshwater ecosystem response to external forcing: evidence from high-resolution multi-proxy lake and peat bog records. Wednesday, 19 July. INQUA XXI, Rome, Italy, 14-20 July 2023.

Read the Abstract - Abstract 237

Harmful cyanobacterial algal blooms (CyanoHABs) have garnered increased public and scientific interest due to the potentially devastating impacts of their toxic secondary metabolites on biota. This has created significant impetus to understand the spatial and temporal drivers associated with their development. While anthropogenic nutrient enrichment and climate-related processes are recognised as important controls on CyanoHABs in modern lake environments, few studies have explored the mechanistic links between specific climatological stressors (e.g. storm events) and past episodes of CyanoHAB development.

This multi-proxy palaeolimnological study is examining the relationships between past toxic algal bloom events, climatological controls (especially historic storms) and catchment-related disturbances in recent (ca. last 500 yr), shallow lake sediment records from New Brunswick, Canada, a maritime region which has seen an increased frequency of lake CyanoHABS in response to land-use change and historic storms.

Palaeo-climatological shifts were investigated in three dated sediment cores using End-member Mixing Analysis (EMMA) of grain-size data, which aids in the determination of depositional pathways associated with hydrological processes (e.g. heavy precipitation) and Itrax X-Ray Fluorescence (XRF), which is useful for detecting palaeo-precipitation and palaeotempest signals. Cyanobacterial responses were inferred from fossil sedimentary pigments and microcystin congeners (cyanobacteria-specific metabolites that preserve in sediments). Ongoing stable isotope analyses (δ¹³C; δ¹⁵N) will further aid in understanding lake productivity shifts and changes in lake sediment provenance.

Our results show that toxigenic metabolites increased by several orders of magnitude in the uppermost (<5 cm) core sediments from all the study lakes. This coincides with fossil pigment shifts, increases in sedimentary phosphorus, and increases in XRF-derived storm air mass signals. In one site (Harvey Lake) notable changes in the upper 2 cm of the record are linked to a major 2014 storm which triggered a significant CyanoHAB event. In another lake, four staggered zones of microcystins may indicate periodic phases of toxigenic cyanobacteria throughout the 0.35 m record.

The mosaic of palaeolimnological proxies being applied in this study will be critical for untangling the complex ecological, sedimentological and geochemical responses of these CyanoHAB-impacted lakes to climate-related stressors. This, in turn, will be integral for understanding their resilience to future change.

236. Roe, H., Logan, K., Patterson, R.T. 2023. Constraining the climatic impacts and season of occurence of the Mazama Ash: insights from laminated marine sediments from the NE Pacific. Session 120: Volcanic impacts on climate and society. Wednesday, 19 July. INQUA XXI, Rome, Italy, 14-20 July 2023.

Read the Abstract - Abstract 236

Tephra deposits from the cataclysmic eruption of Mt Mazama, Oregon at ca. 6,730 ¹⁴C yr BP have been widely reported in sediment records from the western United States and southwestern Canada, and the ash layer represents one of the most important stratigraphic markers for the mid-Holocene in western North America. In spite of a substantial literature on the ash, there remain uncertainties about the character and distribution of the tephra fall-out and the climatic impacts of the ash. In this paper we present the results of a very high-resolution study of a diatomaceous marine sediment core (MD02-2494) from Effingham Inlet, SW Vancouver Island, British Columbia, spanning the interval of the ash. The sediments were deposited under anoxic conditions, are well laminated and preserve a seasonal to sub-seasonal record of primary productivity change, permitting clear delineation of the season of tephra deposition. Scanning Electron Micrographs reveal that the lower boundary of the ash is sharp, suggesting sudden inundation and highlighting a lack of bioturbation and sediment reworking. The ash was deposited as a discrete unit, with little interspersed within it except for some Chaetoceros affinis resting spores and Chaetoceros vegetative cells. This indicates that the ash was deposited en masse rather than gradually or in stages. The volume of ash in the core suggests that the ash likely restricted light availability in the water column and temporarily suppressed primary productivity until it descended through the photic zone. Thin section analysis of diatomaceous sediments spanning a ca. 30 year interval around the ash further confirm that prior to the ash-fall, climate was characterized by warm, dry conditions with significant autumn productivity. However, increased precipitation and enhanced pelagic intrusion into the inlet are inferred around the time of the ash fall, possibly as a result of storm activity associated with high volumes of ash in the atmosphere. These conditions were sustained beyond the impact of the eruption. The presence of the Mazama ash in Effingham Inlet has redefined the known boundaries of the ash-fall in the NE Pacific region, which has not previously been documented this far northwest of the source.

235. Walsh, C.R., Lafond, K.M., Patterson, R.T., McCarthy, F.M.G. 2023. The role of large-scale climate oscillations on the annual deposition of varve couplets in Crawford Lake, Ontario, Canada. Session 126: Sub-annual to decadal records of environmental change. Wednesday, 19 July. INQUA XXI, Rome, Italy, 14-20 July 2023.

Read the Abstract - Abstract 235

Due to its approximately 500-year record of undisturbed annually deposited varve couplets, Crawford Lake, Ontario, Canada is under consideration for the Global Boundary Stratotype Section and Point (GSSP) of the Anthropocene. This new epoch is characterized by the influence of industrialization on the geologic record. Annual varve couplets are divisible into seasonal pairs: light-coloured, calcite-rich laminae deposited in the summer and dark-coloured, organic-rich laminae deposited in the winter.

The thicknesses of these laminae are influenced by environmental and climatic conditions at the site. Varve deposition during the industrial era, specifically between 1870 and 2000, is examined to assess the influence of large-scale natural climate oscillations on the Crawford Lake system during a time of anthropogenic influence. Using cross wavelet transforms (XWTs), the records of seasonal laminae are compared to a variety of climate oscillations to establish any relationships between the two cyclical events. The 11-year Schwabe Solar Cycle (SSC) and the Pacific Decadal Oscillation (PDO) are correlated particularly strongly with the quasi-decadal and interdecadal oscillations in laminae thickness, respectively. Furthermore, interactions between the SSC and PDO influence the phase of the relationship between the SSC and the light laminae. The El Nino Southern Oscillation (ENSO) and the Arctic Oscillation (AO) are also correlated, albeit less strongly, with some interannual to quasi-decadal oscillatory behaviour in the laminae records.

234. Nguyen, A.V., Jautzy, J., Marion, J., Berryman, E., Sanderson, N., Shotyk, W., Patterson, R.T., Galloway, J.M. 2023. Quantitative analyses of testate amoebae as a potential bioindicator of chromium contamination in peatlands. Session 157: Peatlands through time: developmental dynamics and palaeo-environmental reconstruction. Wednesday, 19 July. INQUA XXI, Rome, Italy, 14-20 July 2023.

Read the Abstract - Abstract 234

The largest peatland complex of Canada and the second largest contiguous wetland in the world, the Hudson Bay Lowlands (HBL), spans the northern regions of Manitoba, Ontario and Québec. Large chromite deposits are situated in this highly sensitive environment, which are targeted for mining of critical metals, i.e., chromium. Chromium (Cr) is a common environmental contaminant, predominantly found in aquatic ecosystems as Cr(III) and Cr(VI). Cr(III) is more abundant and is largely immobile precipitated or adsorbed onto mineral, although it can be mobilized by forming complexes with dissolved organic carbon. Conversely, the genotoxic carcinogenic Cr(VI) is mobile in natural waters where reducing materials are limited and can occur as a result of erosion/weathering of chromium deposits or, more commonly, from industrial pollution. The potential fate and impact of Cr in the HBL is currently unknown.

Using pre-mining site in northern Quebec, Ménarik Lake, this study aims to assess natural Cr background and its fate in a typical northern boreal environment. The mobility of Cr due to natural weathering, changes to water table depth, changes in lake sediment redox transition zone, and forest fires will be evaluated using peat natural archives. In particular, testate amoebae, a biological indicator sensitive to climatic and ecological change, will be investigated alongside a comparison of metalloid profiles. Testate amoebae have been extensively used to reconstruct water table depth and have also been shown to be a viable bioindicator for certain metalloid contamination.

The main objectives of this study are to: 1) quantify testate amoebae assemblages in the pre-mining site, 2) develop a transfer function to reconstruct water table depth, 3) determine if testate amoebae can be used as a bioindicator for Cr contamination through multivariate and ordination techniques in conjunction with metalloid concentration data. This will improve our understanding of how the mobility of metals and metalloids are affected in wetlands as they respond to changes in climate and anthropogenic stresses.

233. Patterson, R.T., McCarthy, F.M.G., Head, M.J., Riddick, N., Cumming, B., Hamilton, P., Pisaric, M., Gushulak, C., Leavitt, P.R., Lafond, K.M., et al. 2023. The Anthropocene record preserved in the annually laminated sediment succession of Crawford Lake, Ontario, Canada. Session 40: The Anthropocene as a tool for characterizing recent planetary change and predicting future environmental challenges. Monday, 17 July. INQUA XXI, Rome, Italy, 14-20 July 2023.

Read the Abstract - Abstract 233

The varved sedimentary succession preserved in Crawford Lake, Ontario, Canada is one of 12 potential candidate sections to be selected as the Global boundary Stratotype Section and Point (GSSP) for the Anthropocene series/ epoch, with a proposed base in the mid 20^th century. The sedimentary succession is comprised of seasonally deposited laminations of organic matter capped by calcite that is precipitated each summer in alkaline surface waters when pH and temperature exceed 7.76 and ~15°C respectively. The sedimentary record preserves diverse proxies that reflect environmental change at local to global scales that have been documented to characterize the beginning of the Anthropocene. The spheroidal carbonaceous particles and bulk sediment nitrogen isotope sequence records a significant increase in fossil fuel combustion in the early 1950s. Ratios of 239Pu:240Pu and 14C:12C both peak in the 1960s, coincident with an increase in radioactive fallout from thermonuclear testing; the latter more than compensating for the effects of old carbon in the dolomitic basin of Crawford Lake. The rapid industrial expansion in the North American Great Lakes region that occurred during, and particularly after, WWII, associated with what has come to be known as the Great Acceleration, led to enhanced leaching of terrigenous elements by acid precipitation. A reduction in calcite precipitation and low primary productivity produced thin calcite laminations coeval with the proposed GSSP. The relative thickness of laminations can be linked to the influence of trends and cycles in climate and lake productivity. Time series analysis identified cycles that are attributed to the Quasi-biennial Oscillation (2.3 years), El Nino-Southern Oscillation (2-7 years), the 11-year Schwabe sunspot cycle and Pacific Decadal Oscillation (50-70 years). The absence of fossil pigments from obligately anaerobic purple sulfur bacteria indicates the presence of an oxygenated monimolimnion with elevated bottom-water salinities being responsible for the preservation of varves. This inference is confirmed by water property data collected through the modern lake water column in all seasons. Such an aerobic depositional environment is unusual for a meromictic lake and serendipitously hindered the mobilization of 239Pu in the lake sediments, the proposed primary stratigraphic marker for the Anthropocene.

232. Walsh, C.R., Patterson, R.T. 2023. Linear modelling to predict near-future annual and seasonal weather patterns. Session 66: Data modelling and Inference. Monday, 17 July. INQUA XXI, Rome, Italy, 14-20 July 2023.

Read the Abstract - Abstract 232

Climate modelling is often a computationally intensive process, taking into account a wide variety of variables including incoming/outgoing energy, coupled atmosphere-ocean processes, geography, among other earth processes. Climate modelling, particularly that of a large scale, is often limited to large institutions that can support the development of such computationally intensive work. Furthermore, when attempting to model a smaller scale system, downscaled climate models may be limited by their resolution, particularly when examining a localized system.

We propose an alternative, simplified approach to predicting near-future weather patterns at a local scale. This approach relies on the influence of large-scale climate oscillations on localized weather patterns. We used historical indices of several climate oscillations and a target climate record as a system of linear equations for which a solution was produced. In essence, the solution of the system serves as coefficients which, when applied to the indices of the climate oscillations, produced a model of the target climate record. Using this approach we produced simplified models of the several target climate variables, including average annual, seasonal, and extreme temperatures and precipitation for a given location. The models produced show statistically significant (>95% confidence) correlations with their target climate variable. For the models that were successfully correlated to their target climate record, the Granger Causality test was used to assess whether the model could be used to forecast future climatic events. Statistically significant (>95% confidence) Granger F-statistics suggest several of the models produced may be useful in near-future local climate forecasting.

In addition to providing predictions for local climate, the solution produced from the system of linear equations provided information on the influence of each of the climate oscillations on the target climate variable. When the coefficients are normalized, they provide a proportional representation of their influence on the target climate variable.

This analysis provides a more accessible method of near-future climate modelling that may be used by individuals and organizations that do not have access to developed climate models, or in scenarios where using such models is too computationally intensive.

231. Patterson, R.T., Nasser, N.A., Reinhardt, E.G., Patterson, C.W., Gregory, B.R.B., Mazzella, V., Roe, H., Galloway, J.M. 2023. End-member mixing analysis (EMMA) as a novel tool for the detection of paleo-storms in far inland lake sediment records. Session 182: From Cores to Code: Data-Model Integration to Improve Reconstructions and Forecasts of Coastal Change. Friday, 14 July. INQUA XXI, Rome, Italy, 14-20 July 2023.

Read the Abstract - Abstract 231

Major tropical cyclones and other large storm events cause extensive damage in coastal regions throughout the western North Atlantic Basin. The short instrumental record leaves significant gaps in understanding long-term trends in TC recurrence and intensity, creating uncertainty about modeling future storm trends. Analysis of a >500-year core record from Harvey Lake, located >80 km from the Atlantic coast in southwestern New Brunswick, Canada was carried out using: 1) End Member Mixing Analysis (EMMA) of lake sediment grain size data to identify storm-linked sedimentological processes; and 2) ITRAX XRF derived element/ratios (Fe, Ti, Ca/Sr, Zr/Rb, K/Rb, Br+Cl/Al) associated with precipitation, weathering, catchment runoff and air masses. Three derived end members were correlated to heavy rainfall events (EM01), spring freshet (EM02), and large storm events (EM03). CONISS analysis of the EMMA and XRF core data resulted in recognition of four unique climatic zones distinguished by distinct distributions of storm records and rainfall, weathering, runoff, and air masses. Numerous, major (EM01) rainfall events and (EM03) large storm events characterized the basal core record during the early Little Ice Age (LIAa; Zone 1) phase, terminating at ~1645. A near cessation of heavy rainfall and major events differentiated the subsequent colder LIAb (~1645-1825; Zone 2) and subsequent Little Ice Age Transition (~1825-1895; Zone 3) . A resurgence of major rainfall and large storm events occurred during recovery from the LIA starting in ~1895 (Zone 4). EMMA provides a robust tool for recognition of large stormu and major rainfall events, and greatly expands the potential for paleo-storm activity research well inland from coastal regions.

230. Moore, B.R.S., Evans, D.C., Ryan, M.J., Patterson, R.T., Mallon, J.C. 2023. A juvenile pachycephalosaur (Dinosauria: Ornithischia) skeleton from the upper Maastrichtian Frenchman Formation of Saskatchewan, Canada. 11th Annual Meeting Canadian Society of Vertebrate Palaeontology May 24–26, 2023 Ottawa. p. 25.

Read the Abstract - Abstract 230

Pachycephalosaurs are small (~2–6 m in length), bipedal, ornithischian dinosaurs that lived during the Late Cretaceous in Asia and North America. They are best known for the characteristic fusion of their frontal and parietal bones into a thickened skull dome. These domes are their most commonly preserved element, in part because the less robust elements of their postcrania are more easily lost to post-mortem taphonomic processes. As a result, most inferences about pachycephalosaur growth, anatomy, and phylogenetics are based primarily on skull morphology. In this study we describe a small, partial pachycephalosaur postcranium (CMN 22039) from the uppermost Maastrichtian Frenchman Formation of Saskatchewan. The specimen was discovered by Dale Russell in 1973 at the base of a 6.7 m thick claystone unit, approximately 14 m below the Ferris No. 1 Coal Seam (which approximates the K-Pg boundary in this area). Preserved elements include portions of the dorsal, sacral, and caudal vertebrae, assorted ribs, the complete pelvic girdle, and portions of the hind limb. The specimen was originally assigned to Thescelosaurus, but was subsequently recognized as a pachycephalosaur based on several diagnostic characters, including the presence of a prominent flange projecting medially from the dorsal margin of the ilium, a double ridge-and-groove articulation of the pre- and post-zygapophyses of the dorsal vertebral arches, and an extremely reduced pubis that is nearly excluded from the acetabulum. Osteohistological analysis of the tibia and fibula reveals an immature woven bone texture which lacks any lines of arrested growth or secondary remodeling. This, together, with the unfused neurocentral sutures of the vertebrae and the small size of the specimen (femur length = 84.5 mm), attest to the juvenile status of the individual. A cladistic parsimony analysis including CMN 22039 recovered it in a basal position in Pachycephalosauridae, likely due to its lack of skull characters and its inferred juvenile status. Based on its stratigraphic age, geographic location, size, and postcranial character states, we hypothesize that CMN 22039 represents a specimen of Sphaerotholus buchholtzae and may be the first postcranial skeleton known for this genus. Other possible taxonomic identities for CMN 22039 (Alaskacephale gongloffi, Pachycephalosaurus wyomingensis, and Stygimoloch spinifer) either do not share diagnostic overlapping material with the specimen, or possess conflicting postcranial character states, and cannot be compared on this basis. CMN 22039 demonstrates that diagnostic pachycephalosaur characters are present in the postcranial skeleton even at the earliest stages of ontogeny, probably before the development of the characteristic skull dome. Our study highlights the importance of evaluating the postcranial skeleton during taxonomic identification and shows that pachycephalosaur remains can be recognized at a young age even without cranial material.

229. Warnock-Juteau, T.M., Ryan, M.J., Patterson, R.T., Mallon, J.C. 2023. Redescription of a juvenile hadrosaurid from the Upper Cretaceous of Alberta using computed tomography. 11th Annual Meeting Canadian Society of Vertebrate Palaeontology May 24–26, 2023 Ottawa.

Read the Abstract - Abstract 229

Canadian Museum of Nature specimen CMN 8917 is a partial skull originally described by Charles M. Sternberg (1956) that is one of only several nestling-sized, juvenile hadrosaurines known to date. Sternberg’s original description of the specimen was limited to what was visible externally. We report here on new data obtained using computed tomography (CT) to create 3D models of individual skull elements, allowing for a more thorough description and precise identification of the specimen. Support for its placement within Hadrosaurinae includes the presence of an anterodorsal maxillary process, a maxillary dorsal process that is anteroposteriorly wider than dorsoventrally tall, and a narial vestibule not enclosed within the premaxillary dorsal and lateral processes. The skull also possesses two tooth traits traditionally associated with lambeosaurines (Horner et al. 2004) — secondary ridges on the maxillary and dentary crowns, and denticulation on some of the maxillary crowns. The occurrence of these features in a juvenile hadrosaurine suggests that they are modified during ontogeny, thus calling into question their utility for the taxonomic identification of juvenile specimens. The morphology of the occlusal surface on the dentary teeth of CMN 8917 is similar to those of late nestlings of the hadrosaurine Maiasaura peeblesorum (Horner et al. 2000; Prieto-Márquez and Guenther 2018) and those of many adult hadrosaurids (Erickson et al. 2012), possessing a concave occlusal surface with steeper lingual and shallower buccal wear zones. This differs from the morphology of hatchling lambeosaurine Hypacrosaurus stebingeri, which possess shallow-angle cup-shaped occlusal surfaces (Erickson and Zelenitsky 2014). Differences in occlusal surface morphology between CMN 8917 and H. stebingeri (Erickson and Zelenitsky 2014) at early ontogenetic stages suggests interspecific differences in dental battery development, possibly reflective of dietary differences early in ontogeny.

Literature Cited
Erickson, G.M., B.A. Krick, M. Hamilton, G.R. Bourne, M.A. Norell, E. Lilleodden, and W.G. Sawyer. 2012. Complex dental structure and wear biomechanics in hadrosaurid dinosaurs. Science (American Association for the Advancement of Science) 228:98–101.

Erickson, G.M. and D. Zelenitsky. 2014. Osteohistology and occlusal morphology of Hypacrosaurus stebingeri teeth throughout ontogeny with comments on wear-induced form and function; pp. 422–432 in: D.A. Eberth and D.C. Evans (eds.), Hadrosaurs. Indiana University Press, Bloomington, IN, USA.

Horner, J.R., A. De Ricqlès, and K. Padian. 2000. Long bone histology of the hadrosaurid dinosaur Maiasaura peeblesorum: growth dynamics and physiology based on an ontogenetic series of skeletal elements. Journal of Vertebrate Paleontology 20:115–129.

Horner, J. R., D.B. Weishampel, and C.A. Forster. 2004. Hadrosauridae; pp 438–463 in D.B. Weishampel, P. Dodson, and H. Osmólska (eds.), The Dinosauria 2nd edition. University of California Press Ltd, London, UK.

Prieto-Márquez, A., and M.F. Guenther. 2018. Perinatal specimens of Maiasaura from the Upper Cretaceous of Montana (USA): insights into the early ontogeny of saurolophine hadrosaurid dinosaurs. Peer J 6.

Sternberg, C.M. 1956. A juvenile hadrosaur from the Oldman Formation of Alberta. Bulletin No. 136. Annual Report of the National Museum for the fiscal year 1953–54 136:120–122.

228. Hatton, D.A., Roe, H.M., Patterson, R.T., Leavitt, P.R., McCann, E.T., McMullin, D.R., Reinhardt, E.G., Nasser, N.A., Marshall, M.G. 2023. Elucidating the drivers of shallow lake cyanobacteria bloom events from sediment core records. (May 5). Exploring the Future of Freshwater Harmful Algal Blooms Research. University of Montreal, Interdisciplinary Freshwater Harmful Algal Blooms Workshop (IFHAB) Workshop. May 4, 5.

Read the Abstract - Abstract 228

Harmful cyanobacterial algal blooms (CyanoHABs) in freshwater systems have garnered increased public and scientific interest due to the potentially devastating impacts of their toxic secondary metabolites on biota. This has created significant impetus to elucidate the drivers of CyanoHAB occurrence, and to better understand the resilience of lakes to these toxic bloom events. Dated sediment cores (210Pb, 137Cs,14C) from shallow lake sites in New Brunswick, Canada, a maritime region which has seen an increased frequency of lake CyanoHABs in the last decade, have been examined to explore relationships between past toxic algal bloom events and their controls. Multi-proxy sediment analyses (grain-size, Itrax-XRF; stable isotopes: δ13C; δ15N) were employed to explore the mechanistic links between the drivers of lake change (i.e. climatological stressors and catchment related disturbances) and past episodes of CyanoHAB development. Cyanobacterial responses were investigated using taxonomically specific sedimentary pigments: aphanizophyll (N2-fixing), echinenone (total cyanobacteria), canthaxanthin (nostocales) and myxoxanthophyll (colonial). Microcystin congeners LA, LR, RR, and [Dha7] RR, cyanobacteria-specific metabolites that preserve in sediments, were quantified using liquid-chromatography tandem mass spectrometry (LC-MS). Preliminary results show that in one site, microcystin congeners were detected intermittently throughout the upper 10 cm of the record (representing the last ca. 100 years), before increasing significantly in the upper section of the core towards the present day. These shifts in microcystin concentration broadly coincide with changes in pigment occurrence. Notably, the appearance of aphanizophyll, which indicates water quality degradation and a shift towards nitrogen fixing cyanobacteria, mirrors increases in total microcystins, and a significant spike in microcystin RR. These initial results demonstrate the utility of applying a palaeolimnological approach to reconstructing CyanoHAB events, providing an important opportunity to significantly extend the inferences which can be made from water quality monitoring data alone. This may provide invaluable insights into how lakes might respond to future stressors.

227. Galloway, J.M., Gałka, M., Swindles, G.T., Parsons, M., Taylor, L., Ardakani, O., Wolfe, S.A., Morse, P.D., Amesbury, M., Patterson, R.T., Falck, H., Palmer, M. 2023. Ecohydrological and geological controls on contaminant reservoirs in degrading permafrost peatlands. EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-9683, https://doi.org/10.5194/egusphere-egu23-9683, 2023

Read the Abstract - Abstract 227

Peatlands are important sinks and/or sources of carbon, solutes, and elements of potential concern (e.g., Hg, As, Pb, Cu, Zn) to their surrounding environments. Minerogenic permafrost peatlands that receive input of elements from groundwater and weathering of bedrock and surficial materials accumulate substantial amounts of geogenic-derived elements over millennia, which are then frozen in place. As the Arctic cryosphere thaws due to 21st. c climate warming, understanding of permafrost contaminant reservoirs and tracking their release is a growing challenge due to a lack of knowledge on the cumulative and interacting influences of bedrock and surficial geology, vegetation, climate, fire, and ecohydrology on contaminant accumulation in permafrost peatlands. We examined the Holocene history of two permafrost peatlands from the Northwest Territories, Canada, that are underlain by mineralized volcanic and metasedimentary (Daigle Lake peatland) and unmineralized granitoid (Handle Lake peatland) bedrock. Laboratory methods included pyrolytic speciation to determine the quality and quantity of solid organic matter; plant macrofossil and macroscopic charcoal analysis to reconstruct vegetation, peatland development, and fire history; testate amoebae to reconstruct paleohydrological conditions; and inorganic geochemical analyses to determine elemental concentration over time. Both sites have undergone several marked and broadly coincident hydrological shifts and phases of ecohydrological development. During the early Holocene (ca. 8000-5000 cal BP) initial shallow lake environments at both sites transitioned to rich fen and were colonized by Picea. Elevated concentrations of Zn (up to 65 mg.kg-1), Cu (up to 52 mg.kg-1), As (up to 140 mg.kg-1), and Cr (up to 65 mg.kg-1) occur in the basal lacustrine sediments, particularly at the Daigle Lake peatland that is underlain by mineralized bedrock, but become lower in overlying material that accumulated in a fen setting. Depth to water table increased by almost 30 cm in the Handle Lake peatland between ca. 5900 and 4900 cal BP, coincident with the Holocene Thermal Maximum. At this time, local fires were severe and frequent at both sites and associated with elevated Hg (up to 50 µg.kg-1) in the peat. After this dry interval, the water table rose at ca. 3000 cal BP at the Handle Lake peatland and by ca. 2200 cal BP at the Daigle Lake peatland. Fire occurrence declined, coincident with the relatively cool and wet conditions of the Neoglacial interval. A bog was established at both sites between ca. 2700 and 2200 cal BP. Fire occurrence and the concentration of Hg (up to 175 µg.kg-1), As (up to 300 mg.kg-1), and Zn (up to 50 mg.kg-1) have increased over the past 1000 cal yrs, likely due to a combination of anthropogenic input of As and Hg associated with gold mining in the region and global industrialization as well as warming climate and permafrost thaw. This study illustrates the influence of ecohydrology and bedrock geology on the chemical stores of permafrost peatlands.

2022

226. Patterson, R. T., McCarthy, F.M.G., Head, M., Riddick, N., Cumming, B., Hamilton, P., Pisaric, M., Gushulak, C., Leavitt, P., Lafond, K., Llew-Williams, B., Marshall, M., Heyde, A., Pilkington, P.M., Moraal, J., Boyce, J., Nasser, N.A., Walsh, C.R., Garvie, M., Roberts, S., Rose, N. Cundy, A., Gaca, P., Hajdas, I., Crann, C., Boom, A., Finkelstein, S., McAndrews, J. 2022. Great Acceleration record preserved in the annually laminated sediment succession of Crawford Lake, Ontario, Canada as a candidate locality for the Anthropocene Global Boundary Stratotype Section and Point (GSSP), Focus Session 21. Lakes as archives of the Anthropocene. IAL IPA Joint meeting, Bariloche, Argentina, Nov 27-Dec 1. p. 177.

Read the Abstract - Abstract 226

The varved sedimentary succession preserved in Crawford Lake, Ontario, Canada is proposed as the Global boundary Stratotype Section and Point (GSSP) for the Anthropocene Series/ Epoch, with a proposed base in the mid 20^th century. The sedimentary sequence is comprised of seasonally deposited laminations of organic matter capped by calcite that is precipitated each summer in alkaline surface waters. The record includes diverse proxies that reflect environmental change at global to local scales that have been documented to characterize the beginning of the Anthropocene. The spheroidal carbonaceous particles and bulk sediment nitrogen isotope sequence records a significant increase in fossil fuel combustion in the early 1950s. Ratios of 239Pu:240Pu and 14C:12C both peak in the 1960s, coincident with an increase in radioactive fallout from thermonuclear testing; the latter more than compensating for the effects of old carbon in the dolomitic basin of Crawford Lake. The rapid industrial expansion in the North American Great Lakes region that occurred during, and particularly after, WWII, associated with what has come to be known as the Great Acceleration, led to enhanced leaching of terrigenous elements by acid precipitation. A reduction in calcite precipitation and low primary productivity produced thin calcite laminations coeval with the proposed GSSP. The absence of fossil pigments from obligately anaerobic purple sulfur bacteria indicates the presence of an oxygenated monimolimnion with elevated bottom-water salinities being responsible for the preservation of varves. This inference is confirmed by water property data collected through the modern lake water column in all seasons. Such an aerobic depositional environment is unusual for a meromictic lake and serendipitously prevented the mobilization of 239Pu in the lake sediments, the proposed primary stratigraphic marker for the Anthropocene.

225. Marshall, G. M., Hamilton, B. P.², Lafond, M. K., Nasser, A. N., McCarthy, M.G. M.^,Patterson, R.T. 2022. Annual-scale assessment of mid-20th century impacts on the algal ecology in Crawford Lake, Ontario, Canada. Focus Session 6. Varves records: from tracking natural and anthropogenically induced changes of the environment and climate to improving chronologies of past events. IAL IPA Joint meeting, Bariloche, Argentina, Nov 27-Dec 1. p. 46.

Read the Abstract - Abstract 225

Meromictic Crawford Lake, located in SW Ontario, Canada is characterized by varved sediments, allowing for high-resolution paleoecological studies. Freeze cores, the only coring method available that reliably preserves the fragile laminations representative of summer and winter deposition in the lake, were used to document the siliceous record of diatom and chrysophyte communities at an annual resolution from 1930-1990CE. Stratigraphically constrained cluster analysis showed major assemblage changes that are believed to have been caused by local, regional, and global anthropogenic impacts. The assemblage changes within the siliceous algae are attributed to increased industrial emissions and related effects of acid deposition on the lake’s catchment associated with the Great Acceleration – the massive economic, industrial, and demographic expansion beginning in the mid-20th century which is also coincident with observed increases in other anthropogenic markers found within the lake sediment. The findings reflect major changes in earth systems that the Anthropocene Working Group proposes to use to establish a mid-20th base for the Anthropocene Epoch, providing support for the laminated sedimentary sequence from Crawford Lake as a potential Anthropocene GSSP.

224. Lafond, K., Walsh, C.R., Patterson, R.T., McCarthy, F.M.G., Nasser, N.A., Hamilton, P. 2022. Influence of climatic trends and cycles on the annual varve deposition in Crawford Lake, Ontario, Canada. Focus Session 6. Varves records: from tracking natural and anthropogenically induced changes of the environment and climate to improving chronologies of past events. IAL IPA Joint meeting, Bariloche, Argentina, Nov 27-Dec 1. p. 45.

Read the Abstract - Abstract 224

The proposed Anthropocene Epoch, defined as the interval where marked changes to Earth’s systems driven by human impacts, has left a permanent geological record. Research is underway to select an Anthropocene Global Boundary Stratotype Section and Point (GSSP) with one candidate being the sedimentary sequence preserved in Crawford Lake, Milton, Ontario, Canada. Exceptionally well-preserved annually deposited varves accumulate below the chemocline in this deep karstic basin, and are comprised of productivity influenced dark-colored organic matter laminations, alternating with light-colored calcite precipitated laminations. These laminations archive a record of both natural and anthropogenic change at sub-annual resolution, particularly from the late 19th century onward. A novel high-resolution imaging protocol was used to photograph freeze core CRW19-2FT-B2, collected in February 2019. Individual images were stitched into one cohesive image that was subsequently used to: 1) characterize and identify the chronology of varve couplets deposited between AD 1870 and 2000; 2) document distinctive varves preserved in the core record, including the Holocene-Anthropocene boundary, present throughout the entire lake basin, permitting correlation between existing and future core records; 3) measure the thickness of varves including their distinct dark and light colored laminations; and 4) carry out wavelet and spectral time series analysis based on varve thickness data to identify depositional patterns that can be correlated to trends and cycles in climate and lake productivity. Time series analysis resulted in identification of cycles with statistically significant periodicities that correlate with the Quasi-biennial Oscillation (2.3 years), El Nino Southern Oscillation (2-7 years), the 11-year Schwabe sunspot cycle and Pacific Decadal Oscillation (50-70 years). This research not only provides baseline chronostratigraphic data that definitively archives to the seasonal level the Holocene-Anthropocene Epoch transition preserved in Crawford Lake, but also documents the dynamics of the natural drivers that have influenced deposition in the lake since 1870.

223. Nguyen, A.V., Patterson, R.T., Galloway, J.M., 2022. Paleolimnology of meromictic Teapot Lake, Ontario, inferred using palynological and geochemical variables. Focus Session 17. Varves records: from tracking natural and anthropogenically induced changes of the environment and climate to improving chronologies of past events. IAL IPA Joint meeting, Bariloche, Argentina, Nov 27-Dec 1., p. 158

Read the Abstract - Abstract 223

Teapot Lake is an environmentally sensitive meromictic lake located in the Heart Lake Conservation Area, Brampton, Ontario, Canada. Although there is a long history of indigenous peoples in the area, large-scale clearance of the area surrounding Teapot Lake for agriculture only began in the early 19th century with the arrival of European settlers. The entire region is now highly urbanized, with major highways, industrial areas, aggregate quarries, and housing. A paleoenvironmental record is necessary to analyze the impact of historic and ongoing anthropogenic change to the lake. As there is a paucity of instrumental records prior to the 19th century, proxy indicators such as pollen and sediment geochemistry were used to infer paleoenvironmental changes at Teapot Lake over the Holocene. Four stratigraphically constrained palynological zones (TPZ-1 – 4) were delineated in core TPL C-2, which was collected at the center of Teapot Lake. Based on changes in the relative abundance of pollen genera such as Tsuga, Picea, and Fagus, the region surrounding Teapot Lake experienced warm-dry (TPZ-1, ~8000 – 6000 yr BP), warm-moist (TPZ-2, ~6000 – 3500 yr BP), and then cool-moist conditions (TPZ-3 – 4, ~3500 yr BP – present). Trace element analysis of the core showed intervals of high Fe, P, and Mn, with iron phosphate mineralization in Zone TPL-2 during the Holocene Climate Optimum (HCO) [~7000 – 3000 yr BP]. These higher concentrations of Fe and Mn suggest enhanced interaction between groundwater, the primary recharge source of Teapot Lake, and till, whereas P enrichment suggests longer residence times of migratory birds during the warmer conditions of the HCO. The onset of cool-moist conditions may have limited subsurface water flux and prevented Teapot Lake from receiving dissolved ions from groundwater. This multi-proxy paleoecological approach enabled us to: 1) infer the past vegetation and climate history of the basin, ands 2) reconstruct past hydrological and nutrient conditions in the lake.

222. Shi, D., Weinberg, N., Marshall, M.G., Galloway, J.M., Patterson, R.T. 2022. Paleoclimate reconstruction in Debauchery Bay, Northwest Territories Canada using particle size analysis and geochemical proxies. Focus Session 24. Paleolimnology of high-latitude lakes: sensitive archives of past environmental change. IAL IPA Joint meeting, Bariloche, Argentina, Nov 27-Dec 1., p. 218

Read the Abstract - Abstract 222

Climate variability significantly influences lacustrine systems, impacting physical, chemical, and biological components. This is particularly true of lakes situated in high-latitude northern environments, such as in Walsh Lake, near Yellowknife, Northwest Territories, Canada, where the impact of a changing climate is particularly pronounced. Of particular concern in this region is the widespread contamination by arsenic associated with mineral processing at the former Giant Mine. In this study, high resolution ITRAX XRF and particle size data obtained from two freeze cores recovered from sites in Walsh Lake were analyzed to infer and quantify late Holocene changes within this lake system and implications for the mobility and fate of arsenic and other elements of concern in surface water environments. Through examining proxy data preserved in freeze cores dated to ~1100 cal yr BP, results suggest that arsenic sequestration in sediments has been linked with the presence Fe and Mn (oxy) hydroxides in oxygenated shallow sedimentary environments. Climate warming associated with the Medieval Climate Anomaly and subsequent cooling associated with the Little Ice Age impacted sediment geochemistry, demonstrating climate controls on mobility and sequestration of trace metals in high latitude lacustrine environments.

221. Galloway, J.M., Parsons, M.B., Sanei, H., Weinberg, N., Patterson, R.T., Falck, H. 2022. Mercury deposition from terrestrial reservoirs is a predominant process in sub-arctic and low Arctic lakes: evidence from a spatial survey and a ~1270 year lacustrine sedimentary record from northern Canada. Focus Session 24. Paleolimnology of high-latitude lakes: sensitive archives of past environmental change. IAL IPA Joint meeting, Bariloche, Argentina, Nov 27-Dec 1., p. 219

Read the Abstract - Abstract 221

In sediments of high northern latitude lakes mercury (Hg) is scavenged by autochthonous organic matter, and recent increases in primary production have resulted in increased accumulation of Hg. Terrestrial reservoirs (e.g. permafrost soils, peat bogs) also contain Hg that can be liberated by climate-mediated processes. A combined survey and paleolimnological approach was applied to better understand processes associated with Hg accumulation in lake sediments. Near surface sediments from 66 lakes spanning a 3° latitudinal gradient in the central Northwest Territories (NT), Canada, were sampled and analyzed for elemental geochemistry, Hg, organic matter type, and sedimentary grain size. Total Hg concentration (5.08 to 222.51 μg.kg-1) is significantly (p<0.05) correlated with terrestrially-derived S3 carbon (rs=0.51). Mercury and total organic carbon (TOC), S1, S3, and grain size do not differ significantly (Kruskal-Wallis test) in lake sediments below vs. above treeline, but algal-derived S2 carbon is significantly higher in boreal lakes. The relationship between Hg and S3 indicates export of organic-bound Hg from lake catchments in boreal and tundra environments. In a ca. 1270 year sedimentary record from Walsh Lake, NT, Hg peaks to 546 μg.kg-1 at 1070 CE and 246 μg.kg-1 at 1300 CE, contemporaneous with onset of the Little Ice Age, and concentrations are low (11 to 30 μg.kg-1) in sediments younger than 1400 CE. Mercury is positively associated with clay, sand, and Se, and negatively with silt, S1, S3, and TOC. Principal Components Analysis reveals a relationship between Hg and Cu and Zn. Arsenic is positively correlated to Fe and Mn, suggesting deposition in an oxic setting. Geochemical profiles and relationships in the Walsh Lake core suggest that Hg is associated with clay minerals deposited in a well-oxygenated setting, and partially sourced from mineralized bedrock and derived surficial materials.

220. Vermaire, J.C., Rahman, M., McCann, E., Capy, V., Sivarajah, B., McMullin, D., Patterson, R.T., Vis, C., Smol, J.P. 2022. Increasing cyanobacteria dominance and water quality concerns in artificial lakes along the Rideau Canal system, Canada. Focus Session 32 + 33. Environmental records of the Anthropocene in artificial lakes, IAL IPA Joint meeting, Bariloche, Argentina, Nov 27-Dec 1. p. 263.

Read the Abstract - Abstract 220

The Rideau Canal is a 202 km series of lakes, rivers, and locks that was built in 1832 to link the Ottawa River to the Great Lakes to provide an alternate military route for defending the City of Montreal from potential American attack in the early 1800s. Today the Rideau Canal is a Canadian National Historic Site and primarily used for water related tourism such as fishing and boating. During canal construction the hydrology of the region was changed substantially and water levels were raised in a number of wetlands and rivers to create lakes for boat passage. These artificial lakes now have a large number of recreational properties and homes on their shoreline and residents are increasingly worried about water quality deterioration in these ecosystems. The objective of this study was to assess if artificial lakes along the Rideau Canal are undergoing deterioration in water quality since they were artificial and if there is a greater instance of management intervention in artificial lakes compared to natural lakes in the Rideau Canal. To meet this objective, we analyzed diatoms and cyanobacteria pigments from the artificial Dog Lake and examined recent permit applications for aquatic plant removal in the Rideau Canal. We show using monitoring data that these artificial lakes are some of the most nutrient rich lakes in the Rideau Canal system and that residents are removing macrophyte biomass in these lakes more often than naturally occurring lakes. We further show based on an analysis of a dated sediment core from Dog Lake that this artificial lake has likely been nutrient rich from canal construction, however, cyanobacteria toxins really only start increasing in the around the year 2000, suggesting that recent reported changes in water quality may be influenced by both high phosphorus concentrations and climate warming. Combined these data indicate that artificial lakes may be more susceptible to environmental degradation in the face of a changing environment.

219. Walsh, C.R., Patterson, R.T. 2022. Spatiotemporal patterns in lake ice phenology in New Brunswick and eastern Maine. General Session 2. Present-day lacustrine systems, IAL IPA Joint meeting, Bariloche, Argentina, Nov 27-Dec 1. p. 291.

Read the Abstract - Abstract 219

Annual ice out records (the date of disappearance of ice cover from a water body) from closely- spaced lakes in New Brunswick and eastern Maine were analyzed for regional spatial and temporal patterns. LOWESS regressions indicate that since the 1870s ice out has shifted approximately 5 – 10 days earlier in this region, a pattern consistent with warming climate. Wavelet coherence analysis of the records indicate that ice out was coherent, indicating regional climatic influencers to be the primary forcings of observed ice out patterns. Given the regional coherence, further temporal analyses were carried out for only one lake, Oromocto Lake, as it had the longest ice out record, extending from 1876 to 2021. Cross wavelet analysis was carried out between the Oromocto Lake ice out record and a variety of large-scale climate teleconnections to assess linkages between observed trends and cycles observed in the ice out to specific climatic phenomena. Interannual oscillations in ice out were most strongly influenced by the North Atlantic Oscillation and the El Nino Southern Oscillation, whereas decadal and interdecadal oscillations in ice out were associated with the 11-year solar cycle and the Pacific Decadal Oscillation, respectively.

2021

218. Lafond, K., Patterson, R.T., McCarthy, F.MG., Walsh, C.R., Nasser, N.A. 2021. High-resolution photography as a tool to detect climate trends and cycles archived in a 500-year annually deposited varve record from Crawford Lake, Ontario, Canada. GAC-MAC London, Ontario, Canada, Joint Annual Meeting, Exploring Geosciences Through Time and Space, Abstracts Volume 44, p. 169

Read the Abstract - Abstract 218

In May 2019, the Anthropocene Working Group of the Sub commission on Quaternary Stratigraphy voted in favour of defining a new series/epoch whose base would terminate the Holocene Series/ Epoch. The beginning of the epoch, defined as the interval in geologic deposition where changes to Earth’s systems driven by human impacts have left a permanent geological record, would be in the mid-20th century. Work is underway to identify a GSSP from amongst eleven potential candidate localities from around the world and spanning a variety of geologic settings, one of which is a meromictic lake within the protected Crawford Lake Conservation Area, Milton, Ontario, Canada. The undisturbed accumulation below the chemocline of this deep karstic basin of exceptionally preserved dark-coloured organic matter capped by light-coloured calcite crystals precipitated each summer records both natural and anthropogenic change at sub-annual resolution over the past several centuries. This is of interest in the search for a geologic record of the ‘Great Acceleration’ of population growth, industrialization and globalization that followed the Second World War. A novel high-resolution imaging protocol was used to photograph freeze core CRW19-2FT-B2, collected in February 2019, from the deepest part (23 m) of the lake. Individual images were stitched into one cohesive image using Adobe Photoshop that was subsequently used to: 1) characterize varve couplets deposited between AD 1496 and 2000, identifying the coherent pattern of varves that allow correlation across the deep basin ; 2) measure the thickness of individual varves using pixel counting, which were found to vary between 0.111 and 9.667 pixels, with a mean annual thickness 2.135 pixels; and 3) carry out wavelet and spectral time series analysis using varve thickness data to identify cyclic depositional patterns and relate them to changes in climate and lake productivity that would affect the thickness of the light- and dark-coloured laminae. Wavelet and spectral time series analysis resulted in identification of cycles with statistically significant periodicities that correlate with the Quasi-biennial Oscillation (2.3years), El Nino Southern Oscillation (2-7 years), the 11-year Schwabe sunspot cycle and Pacific Decadal Oscillation (50-70 years). This research provides baseline data on the nature of annual deposition in the lake, as well as time series analysis results that provide an improved discrimination of the natural drivers in the preserved Anthropocene depositional record.

217. Llew-Williams, B., Autumn Heyde, A., Lafond, K., McCarthy, F.M.G., MacKinnon, M., Brand, U., Patterson, R.T., Head, M. 2021 Preservation of Varved Couplets in the Oxygenated Monimolimnion of Crawford Lake: Implications for defining the Anthropocene Epoch. GAC-MAC London, Ontario, Canada, Joint Annual Meeting, Exploring Geosciences Through Time and Space, Abstracts Volume 44, p. 184

Read the Abstract - Abstract 217

The varved sequence of Crawford Lake in a small, deep karstic basin near the Niagara Escarpment in Southern Ontario, is being investigated as a potential GSSP for the proposed Anthropocene Epoch. The dense, highly conductive, alkaline, and slightly saline water chemistry found below the permanent chemocline resembles regional groundwater confirming that the monimolimnion is groundwater sourced. Water recharged into exposed calcareous aquifers ~ 1 km east at the nearby Nassagaweya Canyon, transports oxygenated groundwater into the monimolimnion at concentrations that allow eukaryotic microorganisms to flourish, particularly in winter, when the relatively warm and very nutrient-rich waters provide a refuge. The unique preservation of seasonally laminated couplets in a well-oxygenated setting is of particular interest since the primary marker favoured by the Anthropocene Working Group to define the beginning of this epoch is plutonium fallout from atmospheric thermonuclear testing that is readily mobilized in the anoxic settings that typically allow undisturbed varved sediment accumulation. Above the ~ 15-meter chemocline, the groundwater fed mixolimnion experiences surface water dilution, and substantial seasonal variation with mixing to the chemocline in spring and fall. Although concentrations of Ca+2 and CO3-2 are lower in the mixolimnion, LSI calculations (Feb 2019 – Oct 2020) indicate that calcite crystals precipitate from solution in the slightly basic waters of the epilimnion (~ 0-6 meters) when water temperature exceed ~ 15.2 °C, forming the light-coloured couplet layers on the lakebed. Climate affects the thickness of the light layer, as well as the dark-coloured layers composed primarily of the organic remains of plankton, since it reflects productivity in the lake ecosystem. Productivity is strongly impacted by human activity in the watershed, so the thickness of the dark layer increased dramatically at times of Iroquoian and Colonial settlement, allowing precise and accurate varve-counting (and thus chronological resolution) through the past few centuries. Anoxic bottom waters were assumed essential for the preservation of seasonal laminae, but water column monitoring over the past few years reveals dissolved oxygen measurements sufficient for aerobic respiration. The largest benthic colonizer of the monimolimnion is the nektobenthic ostracod Notodromas monacha which is commonly found in caves and aquifers and appears to have migrated through groundwater flow. The highest hydraulic conductivity, and amount of karstic dissolution, is along the Gasport/Goat Island Fm contact that intersects the basin of Crawford Lake between ~ 16 and 19 m. Crawford Lake is protected by Conservation Halton providing easy access to visitors, interpretive displays on the unique study site, and reconstructed longhouses built by the Iroquoians who farmed the land in the middle of the last millennium, allowing the varves to first become discernible.

216. Marshall, M. Lafond, K., Patterson, R.T., McCarthy, F.M.G. 2021. Impact of the mid-20th century Great Acceleration on Chrysophyte (golden-brown algae) community structure in Crawford Lake, Ontario, Canada- implications for the search for an Anthropocene GSSP. GAC-MAC London, Ontario, Canada, Joint Annual Meeting, Exploring Geosciences Through Time and Space, Abstracts Volume 44, p. 194

Read the Abstract - Abstract 216

Crawford Lake, situated within the Crawford Lake Conservation Area near Milton, Ontario, Canada, has unique characteristics that make it ideally suited to high-resolution paleoecological studies. The seasonally deposited varved sediments in the deep basin of this meromictic lake are currently being considered as a potential Global Boundary Stratotype Section and Point (GSSP) to mark the lower boundary of the proposed Anthropocene Epoch. Golden-Brown Algae (Chrysophyte) communities were examined at annual resolution in varves spanning 1930-1990 CE from freeze core collected from Crawford Lake in February 2019. Stratigraphically constrained cluster analysis showed major assemblage changes within this interval, with one of the highest magnitude changes occurring between varves deposited in 1952 and 1953, coinciding with the first marked increased in 239Pu in sediments due to atmospheric testing of thermonuclear weapons, one of the key markers of the proposed Holocene- Anthropocene boundary. The post-1953 species assemblages within this lake were novel and differed greatly in composition compared to those examined from earlier in the 20th century. These changes in assemblage are attributed to increased industrial emissions and related effects of acid deposition on the lake’s catchment, related to the Great Acceleration – the massive economic, industrial and demographic expansion beginning in the mid-20th century. The findings reported here provide support for the laminated sedimentary sequence from Crawford Lake as a potential Anthropocene GSSP.

215. Miller, C., Parsons, M., Jamieson, H., Ardakani, O., Nasser, N.A., Gregory, B.R.B, Patterson, R.T., Galloway, J.M. Post-depositional mobility of arsenic in a changing climate: implications for cumulative effects assessments at northern mine sites. GAC-MAC London, Ontario, Canada, Joint Annual Meeting, Exploring Geosciences Through Time and Space, Abstracts Volume 44, p. 213-214.

Read the Abstract - Abstract 215

Climate change is affecting the seasonality, biological productivity, and hydrology of lakes in high northern latitudes. These changes may affect the cycling of naturally occurring metal(loid)s and long-term stability of mining-derived contaminants. In mineralized regions, where concentrations of naturally occurring metal(loids) are commonly above environmental quality guidelines, understanding the transport and fate of elements and the drivers of chemical change is especially relevant to guide cumulative effects assessments at past, present and future mine sites. This study integrates arsenic geochemistry, organic petrography, multivariate analysis of climate proxies (particle size, organic matter type and quantity), and radiometric dating (14C and 210Pb) to determine the influence of modern and late-Holocene (5,000 yr cal BP to present) warming episodes on the loading and cycling of arsenic in lake sediments. Integrated paleoclimate and sediment geochemistry reconstructions of two sediment cores collected from mining-impacted lakes in the Courageous Lake Greenstone Belt, Northwest Territories, Canada, document increases in sediment and porewater arsenic concentrations coincident with periods of climate warming. The presence of both primary arsenopyrite and secondary, authigenic arsenic-bearing minerals (framboidal pyrite and Fe-oxyhydroxides; determined by SEM, EMPA and synchrotron-based bulk-XANES) suggests that enhanced weathering and active remobilization of geogenic arsenic occurred in lake catchments during past warming intervals. Detailed characterization of the solid-phase speciation of arsenic and its association with organic matter shows that organic material plays an important role in stabilizing redox-sensitive authigenic minerals (i.e., sulphides and Fe-oxyhydroxides) in lake sediments. Based on the results of this study, we expect that increased concentrations of aquatic- and terrestrially-derived labile organic matter will drive the redistribution of arsenic in shallow lake sediments and result in surface-enrichment of arsenic. These findings are relevant for predicting future climate change-driven variations in metal(loid) cycling in sub-Arctic lakes. Knowledge from this study can be used to improve environmental monitoring and remediation strategies at northern metal mines.

2020

214. Galloway, J.M., Gałka, M., Swindles, G., Amesbury, M., Wolfe, S., Morse, P., Patterson, R.T., Falck, H. 2020 Ecohydrological dynamics of a degrading subarctic peatland: Implications for Arsenic mobility. Session: (HS10.7/BG4.32) Groundwater – Surface Water Interactions: Physical, Biogeochemical and Ecological processes. EGU General Assembly. May 4-8, Vienna. EGU2020. Accepted Presentation – Conference Cancelled due to COVID-19 Pandemic.

Read the Abstract - Abstract 214

Galloway, J.M., Gałka, M., Swindles, G., Amesbury, M., Wolfe, S., Morse, P., Patterson, R.T., Falck, H. 2020 Ecohydrological dynamics of a degrading subarctic peatland: Implications for Arsenic mobility. Session: (HS10.7/BG4.32) Groundwater – Surface Water Interactions: Physical, Biogeochemical and Ecological processes. EGU General Assembly. May 4-8, Vienna. EGU2020. Accepted Presentation – Conference Cancelled due to COVID-19 Pandemic.

A peatland from subarctic Canada (Handle Lake 62°29’26.44”N, 114°23’18.23”W) is a degrading permafrost peatland chosen for detailed study due to a legacy of regional arsenic (As) contamination as a result of almost 8 decades of gold mining. The fate of permafrost peatlands and their element stores is unknown due to complex feedbacks between peat accumulation, hydrology, and vegetation that affect redox state and element mobility. We combine palynology with study of plant macrofossils, testate amoebae, organic matter composition, and bulk geochemistry preserved in a ca. 4180-4972 cal year old peat monolith retrieved from the Handle Lake peatland to reconstruct the ecohydrological dynamics to assess future trajectories of permafrost peat, and contaminant storage or release, in response to current and future warming. Sphagnum riparium macrofossils are rare in modern peat habitats and sub-fossils are rare in paleoecological records. Plant macrofossils of this taxon occur in an 11-cm thick layer together with Sphagnum angustifolium between 43 cm (ca. 3390-3239 cal BP) and 25 cm depth (ca. 2755-2378 cal BP) in the monolith. The S. riparium sub-fossils are present with the hydrophilous testate amoebae species Archerella flavum, Hyalosphenia papilio and Difflugia globulosa that are used to quantitatively reconstruct a water table depth of 0-4 cm below the peat surface. Sub-fossils of S. riparium disappear at ca. 2755-2378 cal BP, likely due to an autogenic trophic shift and succession towards more acidophilic conditions favourable to species such as Sphagnum fuscum and Sphagnum russowii. We interpret the occurrence of S. riparium as an indicator of wet and minerotrophic conditions linked to peatland development form rich fen to oligotrophic bog. Because S. riparium is a key pioneer species of disturbed peatlands that have experienced permafrost degradation it will likely be favoured in northern regions experiencing rapid climate warming. In the palynological record the proportion of Sphagnum-type A spores increases (up to 80%) between ca. 3390-3239 cal BP and ca. 2755-2378 cal BP concurrent with a decline in other Sphagnum-type spores. A peak in micro- and macroscopic charcoal occurs between ca. 3557-3286 cal BP and ca. 3275-2771 cal BP, concurrent with a decline in Picea pollen and an increase in Alnus pollen. Regionally, between ca. 3500 and ca. 2500 cal BP Neoglacial climate prevailed with post-Neoglacial warming at ca. 2500 cal BP. It is therefore possible that regional fire occurrence stimulated permafrost degradation at ca. 3500 cal BP. Background As in the active layer monotlith is ~20-30 ppm. The upper 10 cm of the peat are impacted by aerial deposition of As from ore processing and concentrations range up to ~360 ppm. An increase in the concentration of As in the monolith from ~15-20 ppm at the base of the monolith to ~30-40 ppm during this interval may reflect water table depth dynamics that affected the mobility and fate of this redox sensitive element and/or downward mobility from layers impacted by contamination from mineral processing. Degradation of this permafrost within the Handle Lake peatland will release the currently stored As and other contaminants to the regional environment.

213. Serack, K.M., Patterson, R.T., Gregory, B.R.B., McCarthy, FMG, Yip, B., Nasser, N.A. 2020. Assessing the use of high-resolution imagery in measuring varve thickness for time series analysis. NCUR 2020 Montana State University. March 26-28. Accepted Presentation – Conference Cancelled due to COVID-19 Pandemic.

Read the Abstract - Abstract 213

Serack, K.M., Patterson, R.T., Gregory, B.R.B., McCarthy, FMG, Yip, B., Nasser, N.A. 2020. Assessing the use of high-resolution imagery in measuring varve thickness for time series analysis. NCUR 2020 Montana State University. March 26-28. Accepted Presentation – Conference Cancelled due to COVID-19 Pandemic.

The Anthropocene has been proposed as a new geological epoch, with the base set at AD 1950 to demarcate the profound changes to Earth’s systems driven by human impacts, which will leave a permanent geological record. Nine sites have been proposed as candidates for the Anthropocene Global Boundary Stratotype Section and Point (GSSP; or Golden Spike), with Crawford Lake, located within the protected Crawford Lake Conservation Area, Milton, Ontario, being a prime candidate. A record of annually deposited laminations (varves) within Crawford lake preserve a superb paleolimnological record of both natural and anthropogenic driven changes, where AD 1950 can be easily identified. Four freeze cores were collected in February 2019. A freeze coring approach was used as this is the only coring technology available that can capture an undisturbed record of laminations in these high-gas content sediments without homogenization of the record, particularly in the colloidal soup that exists at the sediment-water interface. A novel high-resolution imaging protocol was used to capture images of both annual and more subtle sub-annual variations in lamina thickness and color. Photo pixel counting was used as part of this approach to both identify and quantify lamina, which would otherwise be impossible using conventional varve assessment methods. Time series analysis was also carried out on the season data to identify and reconstruct trends and cycles archived in the paleolimnological record (e.g. a major change in sedimentation in AD 1820 when the first European settlers cleared the land around the lake; drought cycles such as occurred in the AD 1930s, which are well preserved in the Crawford Lake record). An additional result of this research is an annotated photo-stratigraphic column, which documents the sedimentary record for each year from AD 1200 to the present, which will provide a baseline for future research in Crawford lake.

2019

212. Miller, CB, Parsons, M.B., Jamieson, H.E., Ardakani, O.H., Swindles, G.T., Nasser, N.A., Gregory, B.R.B., Patterson, R.T., Galloway, J.M. 2019. Climate‐related changes in arsenic cycling in northern lakes: Implications for future environmental monitoring of mine sites. Presentation: MP238. Session: Mining environments in a changing climate. Track: Environmental Risk Assessment. SETAC North America. 40^th Annual Meeting. 3-7 November 2019. Toronto. ON. Meeting Program p. 35.

Read the Abstract - Abstract 212

Miller, CB, Parsons, M.B., Jamieson, H.E., Ardakani, O.H., Swindles, G.T., Nasser, N.A., Gregory, B.R.B., Patterson, R.T., Galloway, J.M. 2019. Climate‐related changes in arsenic cycling in northern lakes: Implications for future environmental monitoring of mine sites. Presentation: MP238. Session: Mining environments in a changing climate. Track: Environmental Risk Assessment. SETAC North America. 40^th Annual Meeting. 3-7 November 2019. Toronto. ON. Meeting Program p. 35.

Continued climate warming may affect the cycling of naturally occurring metal(loid)s and the long-term stability of mining-derived contaminants in northern lakes. In sub-Arctic environments, it is not known how the cumulative effects of resource extraction and climate warming will influence geochemical baselines or the cycling of arsenic (As). This study integrates As geochemistry, mineralogy, organic petrography, multivariate analysis of paleoclimate proxies, and radiometric dating to determine the influence of climate on the concentration and cycling of As in lake sediments during the late Holocene (ca. 5,000 yrs. cal BP). Analyses of sediment cores collected from two lakes in the central Northwest Territories document increases in sediment and porewater As coincident with changes in the source and composition of total organic matter. In both lakes, detrital As-bearing minerals (e.g. arsenopyrite and scorodite) are present. However, sediments also contain abundant As-bearing minerals (e.g. framboidal pyrite and Fe-(oxy)hydroxides) formed in situ and mixed porewater oxidation states, suggesting that remobilization of As occurred in lakes where labile organic matter, such as algal-derived lipids and cell walls, increased relative to terrestrially-derived organic matter. These findings provide evidence that past climate warming has influenced the cycling of As in these lakes through its effect on aquatic primary productivity, terrestrial organic matter composition, and catchment erosion rates. This study demonstrates the value of studying long sediment cores from different lakes in a catchment to determine natural variations in background metal concentrations. Knowledge from this study can be used to predict future climate-driven variations in metal(loid) cycling in sub-Arctic lakes and help guide the interpretation of environmental monitoring results at northern metal mines.

211. Patterson, R.T., Neville, L.A., Gammon, P.A., Swindles, G.T., Savard, M.A., Ahad, J., Roe, H.M. 2019. Hydroecologic response of a northern Alberta boreal lake to ocean-atmosphere influenced cycles during recovery from the Little Ice Age. Session: Paleoclimate sub-annual to decadal records of environmental change. INQUA 2019, Dublin, Ireland, Abstract O-0077, Sub-annual to decadal records of environmental change 15:00-15:15 Thursday, 25th July, 2019, Wicklow Meeting Room 3 (Level 2). Chairman: Amy Prendergast

Read the Abstract - Abstract 211

Patterson, R.T. et al. 2019. Hydroecologic response of a northern Alberta boreal lake to ocean-atmosphere influenced cycles during recovery from the Little Ice Age. Session: Paleoclimate sub-annual to decadal records of environmental change. INQUA 2019, Dublin, Ireland, Abstract O-0077, Sub-annual to decadal records of environmental change 13:30-15:15 Thursday, 25th July, 2019, Wicklow Meeting Room 3 (Level 2). Chairperson: Amy Prendergast

A high-resolution (near annual) paleoecological record from “Alberta Lake East”, a boreal upland lake in Northeastern Alberta, Canada archives the ecological history of the lake ca. AD 1875-2010. We use this record to quantify the response of the lake to regional warming during recovery from the colder climate conditions that prevailed there during the Little Ice Age (LIA). Arcellinida (testate lobose amoebae), which are an important intermediary food web component in lakes and preserve well in the sedimentary record, were utilized as a proxy of temporal ecological change in the lake. In the late 19^th century the arcellinidan fauna was dominated by opportunistic centropyxids, which were well suited to the lower productivity LIA conditions. By the early 20^th century, as the polar front had retreated northward at the close of the LIA, the arcellinidan populations became initially dominated by difflugiids and subsequently by Centropyxis tricuspis, indicative of progressively higher productivity conditions associated with longer ice free seasons and warmer summer water temperatures. Time series analysis of temporal changes in the abundance of individual arcellinidan taxa and functional groups obtained from a chronologically well constrained freeze core were used to identify overprinting cyclic climatic influences on lake hydroecology, particularly that of El Niño Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). The ENSO phenomenon is known to have a significant influence on interannual climate variability in western Canada, and has been associated with fluctuations in winter precipitation and temperature in the study region. Positive PDO conditions are associated principally with variation in winter temperatures across the region. Wavelet analysis identified a strong ca. 2-9 year cyclicity that correlates well with ENSO frequency in all arcellinidan proxies, and a weaker ca. 60 year cyclicity that correlates well with PDO frequency within the difflugiid and C. tricuspis populations. Correlation analysis between arcellinidan populations and the Nino 3.4 and PDO instrumental data revealed that taxa associated with higher productivity (e.g. difflugiids) were negatively correlated with +ENSO and +PDO conditions, which are associated with decreased precipitation and reduced nutrient runoff from lake catchments. The close relationship between arcellinidan ecology and subdecadal changes in climate at Alberta Lake East demonstrates the high sensitivity of northern lake ecosystems to climate variability.

210. Roe H.M., Patterson, R., Trainor, P., Vermaire,J., Patterson, R.T., Wolfe, S. 2019. Understanding forest responses to climate change in sub-arctic Canada: integrated palaeoecological and ecological records from the Northwest Territories INQUA 2019, Dublin, Ireland, Abstract O-2035, Session: Connecting palaeoecology with present and future ecosystem dynamics Liffey Meeting Room 3 (Level 1). 10:00-10:45, Saturday, 27th July, 2019, Wicklow Meeting Room 3 (Level 2). Chairman: Althea Davies

Read the Abstract - Abstract 210

Roe H.M., et al. 2019. Understanding forest responses to climate change in sub-arctic Canada: integrated palaeoecological and ecological records from the Northwest Territories INQUA 2019, Dublin, Ireland, Abstract O-2035, Session: Connecting palaeoecology with present and future ecosystem dynamics Liffey Meeting Room 3 (Level 1). 9:00-10:45, Saturday, 27th July, 2019, Wicklow Meeting Room 3 (Level 2). Chairman: Althea Davies

High boreal environments are particularly susceptible to predicated temperature increases, where ecosystem interactions are both spatially variable and driven by episodic natural disturbances. Palaeolimnological studies from sites above the modern treeline in the Northwest Territories have revealed the dynamic nature of the response of the boreal ecozone to inferred climate warming during the mid-Holocene. However, knowledge of the character and timing of landscape evolution in the first few millennia after deglaciation remain poorly understood. This period was characterised by complex environmental changes as glacial meltwaters drained from the region and boreal forest communities migrated northwards in response to climate amelioration. This paper will draw upon peatland and lake sediment records from a transect of sites (n=9) that extends from the central Great Slave Lowlands to the tundra ecozone ca. 200 km to the northeast to (i) provide new insights into rates of peatland initiation, vegetation colonisation and treeline mobility in the early to mid Holocene; and (ii) appraise the utility of a range of proxies (pollen, stomata, chironomids, diatoms and charcoal) for understanding climate-environment interactions during this interval. Such insights have the potential to provide important context for understanding the impacts of future climate change in the region. Quantitative temperature reconstructions will be presented that are derived from fossil chironomid assemblages from three lakes (Matthews Lake, Horseshoe Lake and Frame Lake). These show that during the early Holocene (prior to ca. 8000 cal yr BP) temperatures exceeded present conditions by ca. 1-2 °C, whilst palynological data, particularly evidence from fossil stomata, reveal a more dynamic treeline in the mid-Holocene than previously documented. Pollen data from a transect of modern lakes (n=57) from the same region helps to better contextualise some of the inferred changes in Holocene forest dynamics, but also highlights some of the difficulties of using arboreal pollen data to reconstruct treeline position. Together the records provide a basis for further re-assessment of the character, timing and impacts of regional climate fluctuations in this sensitive northern region, and underline the benefits of integrating long-term palaeoecological data with an understanding of modern ecological processes.”]

209. McCarthy, F., Head, M., Patterson, R.T., McAndrews, J., Krueger, A., Heyde, A., Turton, C., Alderson, A., Cocker, S., Tepavcevic, M. 2019. Defining the Anthropocene at Crawford Lake as an integral part of the Niagara Escarpment Geoheritage. Session SS-GS01: Geoheritage: From local to international Conveners: Conveners, Desrochers, A., Verpaelst, P., Malo, M.GAC-MAC-IAH. Where Geosciences Converge. Abstracts and Program. May 12-15, Quebec City, Quebec, vol. 42, p. 141

Read the Abstract - Abstract 209

McCarthy et al. 2019. Defining the Anthropocene at Crawford Lake as an integral part of the Niagara Escarpment Geoheritage. Session SS-GS01: Geoheritage: From local to international Conveners: Conveners, Desrochers, A., Verpaelst, P., Malo, M.GAC-MAC-IAH. Where Geosciences Converge. Abstracts and Program. May 12-15, Quebec City, Quebec, vol. 42, p. 141

Many studies have been conducted on Crawford Lake since the pollen of Zea mays and other cultivars from the middle of the last millennium were identified in the early 1970s. Varved sediments in the deep dolostone basin of this small lake near the edge of the Niagara Escarpment in Milton, Ontario provide annual/seasonal resolution through the last millennium, dating Iroquoian agricultural settlement between 1268 and 1486 CE and EuroCanadian land clearing beginning ~ 1822 CE. Exceptionally diverse assemblages of organic-walled microfossils including rotifer loricae and cellulosic dinoflagellate thecae characterize this Holocene Lagerstätte, which contains the oldest viable cysts of dinoflagellates germinated from varves dating to the early 1820s. In addition to subannual resolution, other attractive features of the Crawford Lake succession include its accessibility and protection by Conservation Halton since the first archeological investigation discovered artifacts and evidence of longhouses. The reconstructed Iroquoian village is a popular attraction, and the unique lacustrine environment and the micropaleontological research that led to the discovery of the site at the Conservation Authority’s Interpretive Centre feature in display materials along the boardwalk around the lake. The geoheritage aspect of the site remains undervalued, however. The varved record of Crawford Lake is being investigated as a potential GSSP candidate for the Anthropocene Series, as required to formalize the term Anthropocene as a potential new unit of geologic time, with a proposed base at AD ~ 1950 (the “bomb spike”). It is anticipated that this initiative, keenly debated among the geoscience and broader community, will draw attention to geoheritage and its value in the broader societal context, particularly in clearly distinguishing between diachronous anthropogenic impact and the proposed boundary between the Holocene and Anthropocene Series.

2018

208. Galloway, J.M., Palmer, M., Swindles, G.T., Jamieson, H.E., Parsons, M.B., Sanei, H., Macumber, A.L., Patterson, R.T., Falck, H. 2018. Organic matter control on the distribution of arsenic in lake sediments impacted by ~65 years of gold ore processing in subarctic Canada. in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 2018. 46th Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume.

207. Neville, L.A., Kelly, S., Patterson, R.T. 2018. Cycles of Climate. RemTech – Remediation Technologies Symposium. Fairmont Banff Springs Hotel, Banff, Alberta. Oct 10-12.

206. Gregory, B.R.B., Patterson, R.T. 2018. Testing the response of Arcellinida communities to arsenic in a simulated lake environment. Theme Session: Functional traits, morphometrics and novel analytical approaches. Thursday, September 13. Focused Meeting: 9th International Symposium on Testate Amoebae (ISTA 9). 10 – 14 September 2018.

205. Steele, R., Nasser, N.A., Patterson, R.T. 2018. Semi-automated analysis of lacustrine Arcellinida (testate lobose amoebae) using FlowCam technology. Theme Session: Functional traits, morphometrics and novel analytical approaches. Thursday, September 13. Focused Meeting: 9th International Symposium on Testate Amoebae (ISTA 9). 10 – 14 September 2018.

204. Patterson, R.T. 2018. (Keynote Speaker). The future of Arcellinida in applied paleolimnology: achieving high-quality and high-resolution research outcomes on a budget. Theme Session: Ecology and Bioindication. Wednesday, September 12. Focused Meeting: 9th International Symposium on Testate Amoebae (ISTA 9). 10 – 14 September 2018.

203. Cockburn, C., Gregory, B.R.B., Nasser, N.A., Patterson, R.T. 2018. Arcellinida (testate lobose amoebae) as a salt contamination monitoring tool in the ‘Salt Belt’ lakes of northeastern North America. Theme Session: Ecology and Bioindication. Wednesday, September 12. Focused Meeting: 9th International Symposium on Testate Amoebae (ISTA 9). 10 – 14 September 2018.

202. Nasser, N.A., Patterson, R.T. 2018. Quantification of arsenic-tolerance limits of lacustrine Arcellinida (testate lobose amoebae): implications for environmental monitoring. Theme Session: Ecology and Bioindication. Wednesday, September 12. Focused Meeting: 9th International Symposium on Testate Amoebae (ISTA 9). 10 – 14 September 2018.

201. Nasser, N.A., Cullen, J., Patterson, C.W., Patterson, R.T., Roe, H.M., Galloway, J.M. 2018. Assessing temporal changes in Arcellinida (testate lobose amoebae) standing crop in homogenous lacustrine environments (Flash poster presentation). Theme Session: Ecology and Bioindication. Wednesday, September 12. Focused Meeting: 9th International Symposium on Testate Amoebae (ISTA 9), Microbiology Society and International Society of Protistologists. 10 – 14 September 2018, Program and Abstracts p. 43.

200. Wen, A., Gregory, B.R.B., Patterson, R.T. 2018. Intralake hydroecological controls on the distribution of Arcellinida (testate lobose amoebae) in a temperate eastern North American lake (Flash poster presentation). Theme Session: Ecology and Bioindication. Wednesday, September 12 (Poster). Focused Meeting: 9th International Symposium on Testate Amoebae (ISTA 9). 10 – 14 September 2018.

199. Roe, H.M., Elliott, S.M., Patterson, R.T. 2018. Reassessing the vertical distribution of testate amoeba communities in acrotelmic peats in eastern Canada (Flash poster presentation). Theme Session. Palaeoecology and Palaeoclimatology. Tuesday, September 11. Focused Meeting: 9th International Symposium on Testate Amoebae (ISTA 9). 10 – 14 September 2018.

198. Nasser N.A., Patterson R.T., Galloway J.M., Palmer M.J., Roe H.M., Falck H., Sanei H. Tolerance limits of Arcellinida (testate lobose amoebae) to lacustrine arsenic contamination in the Canadian subarctic Session S4 Syntheses of human-environment interactions during the Holocene. Joint Meeting of the Canadian and American Quaternary Associations. Crossing Borders in the Quaternary. Carleton University, Ottawa, Ontario, Canada. August 7-11, 2018. Abstracts and Program. p. 71.

197. Steele, Riley E., Nasser, Nawaf A., Patterson, R.T. 2018. Flowcam technology for semi-automated Arcellinida (testate lobose amoebae) Session S6 Reducing the Time to Science. Joint Meeting of the Canadian and American Quaternary Associations. Crossing Borders in the Quaternary. Carleton University, Ottawa, Ontario, Canada. August 7-11, 2018. Abstracts and Program. p. 87.

196. Gregory, B.R.B., Patterson, R.T., Reinhardt, E.G., and Galloway, J.M. 2018. Itrax-XRF-CS analysis of freeze cores recovered from Control Lake, NT, show that arsenic variability in sediment is linked to climate change. Session S10 High-resolution Records of the Common Era. Joint Meeting of the Canadian and American Quaternary Associations. Crossing Borders in the Quaternary. Carleton University, Ottawa, Ontario, Canada. August 7-11, 2018. Abstracts and Program. p. 45.

195. Mazzella, V., Gregory, B.R.B., Samson C., Patterson,R.T., Macumber,A.L., Roe,H.M., Galloway, J.M. 2018. Integrated tools to determine the spatio-temporal controls on cyanobacteria blooms in an eastern Canadian lake. Session S14 Environmental Geology and Paleoecology. Joint Meeting of the Canadian and American Quaternary Associations. Crossing Borders in the Quaternary. Carleton University, Ottawa, Ontario, Canada. August 7-11, 2018. Abstracts and Program. p. 64.

194. Galloway, J.M., Gałka, M., Swindles, G.T., Wolfe, S.A., Morse, P.D., Patterson, R.T., Falck, H., Kung, L. 2018 Ecohydrological dynamics of a degrading subarctic peatland: Implications for Arsenic mobility. Theme Session (August 8): Applications of Palynology to Environmental Science. Chairs: Steve Stukins and Gunn Mangerud. 51st Meeting American Association of Stratigraphic Palynologist (AASP) – The Palynological Society (TPS) joint meeting with the Canadian Association of Palynologists (CAP), Calgary, Alberta, August 5th-10th.

193. McCarthy, F.M.G., Neville, L.A., Garner, C.S., Patterson, R.T. 2018. Pollen and non-pollen palynomorphs as biomonitors in oil sands operations. Theme Session (August 8): Applications of Palynology to Environmental Science. Chairs: Steve Stukins and Gunn Mangerud. 51st Meeting American Association of Stratigraphic Palynologist (AASP) – The Palynological Society (TPS) joint meeting with the Canadian Association of Palynologists (CAP), Calgary, Alberta, August 5th-10th.

192. Walsh, C., Patterson, R.T. 2018. Climate and extreme weather trends across eastern Canada and the north-eastern United States. Technical Session 5a (Environmental). Advances in Earth Science Research Conference AESRC 2018 University of Ottawa, March 23-25.

191. Steele, Riley E., Nasser, Nawaf A., Patterson, R.T. 2018. Rapid Identification and Quantification of Lacustrine Arcellinida (Testate Lobose Amoebae) using FlowCAM. Technical Session 3 (Paleontology). Advances in Earth Science Research Conference AESRC 2018 University of Ottawa, March 23-25.

190. Mazzella, V., Gregory, B.R.B., Samson, C., Patterson, R.T., Macumber, A.L., Roe, H.M., Galloway, J.M. 2018. High Resolution Intra-Lake Assessment of Spatial Heterogeniety in Harvey Lake, New Brunswick, Canada: Implications for Sampling Design. Technical Session 3 (Paleontology). Advances in Earth Science Research Conference AESRC 2018 University of Ottawa, March 23-25.

2017

189. Patterson, R.T., Swindles, G.T. 2017. The contribution of ‘Citizen Scientists’ to determining the influence of ocean-atmospheric oscillations on lake ice phenology in eastern North America. Past Global Changes (PAGES) 5^th Open Science Meeting, Zaragoza, Spain, 9-13 May 2017.

188. Gregory, B.R.B., Patterson, R.T., Galloway, J.M., Nasser, A.L., Macumber, A.L., Falck, H., Sexton, A. 2017. Understanding the response of arsenic in sub-Arctic lakes to Holocene climate variability. Geological Association of Canada – Mineralogical Assosiation of Canada Annual Meeting, Kingston, May 14-18.

187. Miller, C.B., Parson, M.B., Jamieson, H.E., Galloway, J.M., Patterson, R.T. 2017. Geochemical baselines and metal(loid) mobility in a changing northern climate. Geological Association of Canada – Mineralogical Association of Canada Annual Meeting, Kingston, May 14-18.

186. Patterson, R.T., Nasser, N., Galloway, J.M. 2017 Indigenous traditional knowledge and climate change. 68^th Spring Conference – Diversity. April 28-30. INVITED LECTURE

185. Nasser, N.A. Patterson, R.T., Galloway, J.M., Gregory, B.R.B., Macumber, A.L. Palmer, M., Falck, H. 2017. High-Resolution Inter-Lake Assessment of Arcellinida (Testate Lobose Amoebae) as Bio-Indicators of Legacy Mine Contamination in the Yellowknife Region, NT, Canada. Ottawa-Carleton Student Northern Research Symposium (OCSNRS 2017). March 10, 2017, Carleton University. BEST ORAL PRESENTATION AWARD

184. Gregory, B.R.B., Patterson, R.T., Galloway, J.M., Nasser, N.A., Macumber, A.L., Falck, H., Sexton, A. 2017. Integrated ITRAX-XRF and freeze coring as a method for high quality, rapid, and cost effective determination of baseline levels for elements of concern. Conference: 44th Annual Geoscience Forum. Yellowknife, NWT, Canada. November.

183. Galloway, J., Palmer, M., Swindles, G.T., Sanei, H., Jameison, H.E., Parsons, M., Macumber, A.L., Patterson, R.T., Falck, H., 2017. Late Holocene climate and chemical change at high latitudes: case studies from contaminated sites in subarctic and arctic Canada. European Geological Union Annual Meeting, Vienna. Session April 2017.

182. Swindles, G.T., Morris, P.J., Whitney, B., Galka, M., Galloway, J.M., Gallego-Sala, A., Macumber, A.L., Mullan, D., Smith, M.W., Amesbury, M., Roland, T., Sanei, H., Patterson, R.T., Parry, L., Charman, D.J., Lopez, O.R., Valderamma, E., Watson, E.J., Lähteenoja, O., Baird, A.J. 2017. Holocene development of Amazonia’s oldest peatland. European Geological Union Annual Meeting, Vienna. Session SSS5.6 – Peatlands and wetlands in the tropics and beyond: biogeochemistry, ecology, and carbon cycles. Wednesday, 26 April.

2016

181. Gregory, B.R.B., Patterson, R.T., Galloway, J.M., Nasser, A.L., Macumber, A.L., Sexton, A., Sutter, T., Falck, H. 2016. Integrated ITRAX-XRF and freeze coring as a method for High quality, rapid, and cost effective (QRC) determination of background levels of elements of concern: Testing linear and multivariate calibration methods in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 2016. 44th Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume.

180. Patterson R.T., Nasser N.A., Gregory B.R.B, Menard, E., Macumber A.L., Hutchinson, S., Galloway, J.M., Roe, H.M. , Falck, H., Palmer, M.J. 2016. Quantifying anthropogenic versus natural impacts on northern lakes: new tools for high quality, rapid collection and cost-effective (QRC) data acquisition. in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 2016. 444th Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume.

179. Roe, H.M., Patterson, R.T., Edwards, R.J., Ruffell, A., Graham, C., Nasser, N. 2016. Integrated protocols for monitoring the impacts of landfill-derived leachates in intertidal environments. Environmental Geosciences. 35^th International Geological Congress, 27 August – 4 September, 2016. Cape Town South Africa.

178. Patterson, R.T. 2016. Integrated freeze core –ITRA micro-XRF scanning: a non-destructive and cost effective method of baseline geochemical determination in the low-sedimentation environment of a legacy mining camp in Subarctic Canada. Environmental Geosciences. 35^th International Geological Congress, 27 August – 4 September, 2016. Cape Town South Africa.

177. Patterson, R.T., Swindles, G.T. 2016. “Ice out”: the contribution of citizen scientists to our understanding of climate change. EGU General Assembly Conference Abstracts, Vienna, Austria, v. 18, p. 10892.

176. Roe, H.M., Patterson, R.T., Nasser, N., Edwards, R.J., Graham, C. 2016. Development of integrated protocols to track the deposition and impacts of metal contaminants in tidal riverine environments. EGU General Assembly Conference Abstracts, Vienna, Austria, v. 18, p. 15439

175. Galloway, J.M., Sanei, H., Parsons, M., Swindles, G.T., Macumber, A.L., Patterson, R.T., Palmer, M., Falck, H. 2016. Examining the relationship between mercury and organic matter in lake sediments along a latitudinal transect in subarctic Canada. EGU General Assembly Conference Abstracts, Vienna, Austria, v. 18, p. 9948.

174. Patterson, R.T., 2016. KEYNOTE SPEAKER. “Ice Out”: The contribution of citizen scientists to our understanding of climate change. Advances in Earth Sciences Research Conference (AESRC), Carleton University. April 1-3, 2016.

173. Nasser, N.A., Patterson, R.T., Macumber, A.L., Gregory, B.R.B., Galloway, J.M. 2016. High Spatio-Temporal Resolution Assessment of Arcellinina (Testate Amoebae) as Bio-Indicators of Legacy Mine Contamination in the Canadian Subarctic: Implications for Environmental Monitoring. Advances in Earth Sciences Research Conference (AESRC), Carleton University. Apri 1-3, 2016.

172. Gregory, B.R.B., Patterson, R.T., Macumber, A.L., Nasser, N.A., Galloway, J.M. 2016. Integrated ITRAX – XRF and Freeze Coring as a Method of Understanding Arsenic Variability in the Subarctic. Advances in Earth Sciences Research Conference (AESRC), Carleton University. Apri 1-3, 2016.

171. Mazzella, V., Macumber, A.L., Patterson, R.T., Roe, H.M. 2016. Analysis of Grain Size and Metals of Concern in Harvey Lake, N.B. Advances in Earth Sciences Research Conference (AESRC), Carleton University. Apri 1-3, 2016.

2015

170. Macumber, A.L., Galloway, J.M., Crann, C.C., Swindles, G.T., Falck, H., Palmer, M.J., Patterson, R.T. 2015. Examining the Relationship Between Climate Variability and Metal Cycling in Pocket Lake. in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 2015. 43rd Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume, p. 62.

169. Nasser, N.A., Patterson, R.T., Macumber, A.L., Gregory, B.R.B., Galloway, J.M., Falck, H . 2015. High Spatio-Temporal Resolution Assessment of Arcellinina (Testate Amoebae) as Bio-Indicators of Legacy Mine Contamination in the Canadian Subarctic: Implications for Environmental Monitoring. in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 2015. 43rd Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume, p. 73.

168. Palmer, M.J., Galloway, J.M., Jamieson, H.E., van den Berghe, M., Patterson, R.T., Kokelj, S.V., Swindles, G.T., Falck, H., Howell, D., Stavinga, D.B., Nasser, N.A., Roe, H.M. 2105. The Concentration of Arsenic in Lakes of the Yellowknife Area. in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 2015. 43rd Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume, p. 81.

167. Patterson, R.T., Nasser, N.A., Gregory, B.R.B., Sabourin, M., Menard, E., Macumber, A.L., Cott, P.A., Ellis, S., Hanna, B., Galloway, J.M., Falck, H., and Palmer, M.J., 2015. Who Killed Frame Lake? Progress Report on Efforts to Rehabilitate an Important Yellowknife Recreation Area. . in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 2015. 43rd Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume, p. 83

166. Roe, H.M., Patterson, R.S., Trainor, P., Wolfe, S.A., Patterson, R.T., Vermaire, J.C., 2015. Reconstructing Early to Mid-Holocene Landscape Evolution in the Central Northwest Territories, Canada: Insights From Biological Proxy Data. in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 2015. 43rd Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume, p. 91.

165. Sulphur, K.C., Goldsmith, S.A., Galloway, J.M., Hills, L.V., Macumber, A.L., Swindles, G.T., Patterson, R.T., Falck, H. 2015. Holocene Fire Regimes and Treeline Migration Rates in Subarctic Canada. in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 2015. 43rd Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume, p. 102.

164. Galloway, J.M., Patterson, R.T. 2015. Geoscience Tools for Supporting Environmental Risk Assessment of Metal Mining. in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 43rd Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume, p. 119.

163. Gregory, B.R.B., Patterson, R.T., Galloway, J.M., Falck, H., Setterfield, T., Nasser, N.A., and Macumber, A.L. 2015. Integrated Freeze Core – Itrax Micro-XRF Scanning as a Non-Destructive Method to Determine Baseline Geochemical Concentrations: Preliminary Results From Milner and Daigle Lake, Yellowknife, Northwest Territories. in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 43rd Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume, p. 119.

162. Macumber, A.L., Crann, C., Cutts, J.A., Courtney Mustaphi, C.J., Nasser, N.A., Galloway, J.M., Falck, H., Patterson, R.T. 2015. An Assessment of the Accuracy of Radiocarbon Dates From the Central Northwest Territories Based on the Occurrence of the A.D. 833-850 White River Ash in Pocket Lake, Yellowknife, NT. in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 43rd Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume, p. 131

161. Nasser, N.A., Patterson, R.T., Macumber, A.L., Gregory, B.R.B., Sabourin, M., Menard, E., Galloway, J.M., and Falck, H. 2015. Intra-Lake Assessment of the Utility of Arcellinina (Testate Amoebae) as Bio-Monitors of Lacustrine System Health in Frame Lake, Yellowknife, Northwest Territories, Canada. in: Irwin, D., Normandeau, P.X. and Gervais, S.D. (compilers), 43rd Annual Yellowknife Geoscience Forum Abstracts; Northwest Territories Geological Survey, Yellowknife, NT. YKGSF Abstracts Volume, p. 136

160. Patterson, R.T., Swindles, G.T. 2015. Influence of ocean–atmospheric oscillations on regional hydroecology in eastern North America derived from citizen scientist collected lake “ice out” records. Session S-15-04 (Aug 5). Integrating Lake Sediment and Other Records as a Foundation for Understanding the Functioning of Regional Social-Ecological Systems. 13th International Paleolimnology Symposium (IPS2015). Lanzhou University, Lanzhou China, August 4-7.

159. Roe, H.M., Patterson, R.T. 2015. Foraminifera as historical pollution indicators in coastal wetlands Session C02 Coastal Wetlands, 28 July.

158. Macumber, A.L., Patterson, R.T. 2015. The Holocene Climate Optimum as archived by lacustrine sedimentary records from the central Northwest Territories, Canada.

157. Neville, L.A., Gammon, P., Patterson, R.T., Swindles, G.T. 2015. Climate cycles drive aquatic ecologic changes in the Fort McMurray region of northern Alberta, Canada. GeoConvention 2015, Telus Convention Centre, Calgary, Alberta, May 4-8.

156. Patterson, R.T., Neville, L.A., Gammon, P., Swindles, G.T., Macumber, A.L. 2015. Influence of the Pacific Decadal Oscillation and El Niño-Southern Oscillation on lacustrine hydroecologic cycling in Alberta. PACLIM 2015 – Droughts: Reconstructing the past, monitoring the present, modeling the future. Twenty-Seventh Pacific Climate Workshop, Asilomar State Conference Grounds, Pacific Grove, California, March 8-11th.

155. Galloway, J.M., Cooney, D., Falck, H., Howell, D., Jamieson, H., Macumber, A., Nasser, N., Palmer, M., Patterson, R.T., Parsons, M., Roe, H.M., Sanei, H., Spence, C., Stavings, D., Swindles, G.T. 2015. Late Holocene climate and chemical change at high latitudes: case studies from contaminated sites in subarctic and arctic Canada. EGU General Assembly Conference Abstracts, Vienna, Austria,, v. 17, 1843 p.

2014

154. Galloway, J.M., Swindles, G.T., Patterson, R.T., Macumber, A.L., Falck, H., Roe, H.M. 2014. Late Holocene climate change across ecotone gradients and implications for future change in the central subarctic of Canada. School of Geography Leeds University Seminar. November.

153. Patterson, R.T., Swindles, G.T. 2014. Plenary Talk. Influence of ocean-atmospheric oscillations on lake ice out records in eastern North America. The Science of Groundwater. Latornell Geoscience Day, Nov 17th Alliston, Ontario, p. 5.

152. Nasser, N.A., Patterson, R.T., Macumber, A.L., Galloway, J.M., Roe, H,M. 2014. Utility of arcellaceans (shelled protists) as a tool for monitoring arsenic and heavy metal contamination. The Science of Groundwater. Latornell Geoscience Day, Nov 17th Alliston, Ontario, p. 7.

151. Patterson, R.T., Galloway, J.M., Ziten, C.T., Watchorn M.S., Clark, I.A., Hamilton, P.B., Roe, H.M. 2014. The Holocene paleolimnologic and ecohydrologic history of a meromictic lake, Brampton, Ontario. The Science of Groundwater. Latornell Geoscience Day, Nov 17th Alliston, Ontario, p. 6.

150. Patterson, R.T., Neville, L.A., Gammon, P., Swindles, G.T., Macumber, A.L. 2014. Arcellacea as proxies of ocean-atmosphere influenced hydroecologic cycles in a northern Alberta, Canada lake. 7th International Symposium on Testate Amoebae, Poznan, Poland, 8-12 September 2014, p. 29.

149. Gregory, B.R.B., Reinhardt, E.G., Patterson, R.T., 2014. High-resolution ITRAX XRF scanning of sediment cores: tracking trace metal contamination and remediation in sedimentary records. The Science of Groundwater. Latornell Geoscience Day, Nov 17th Alliston, Ontario, p. 7.

148. Galloway, J.M., Patterson, R.T. 2014. Impact of flooding in southwestern Alberta: past present and future perspectives. GeoAlberta 2014: Learn, Share, Network. October 27-29, Calgary, Alberta. Monday Oct. 27.

147. Roe, H.M. Patterson, R.T., Swindles, G.T. 2014. Tracking water quality degradation in urban lakes: application of benthic protozoans for biomonitoring in the GTA. The Science of Groundwater. Latornell Geoscience Day, Nov 17th Alliston, Ontario, p. 5.

146. Macumber, A.L., Patterson, R.T., Galloway, J.M, Vermaire, J.C., Falck, H., Clark, I. 2014. 7,500-year record of Canadian Subarctic climate dynamics as evidenced by fossil Arcellacea, isotopic signatures and sediment particle size. 7th International Symposium on Testate Amoebae, Poznan, Poland, 8-12 September 2014, p. 29.

145. Patterson, R.T., Galloway, J.M., Spence, C., Kokelj, S., English, M., Wolfe, S., Morse, S., Morse, P., Sanei H, Parson, M., , Nasser, N., Cooney, D., Crann, C., Roe, H.M., Swindles, G.T., Hamieson, H., Howell, D., Stavinga, D., Palmer, M., Falck, H., Mapping the geochemistry of lake seidments near Yellowknife, Northwest Territories, Understanding the Nature, Extent and Fate of Legacy Contamination Near Yellowknife, NWT. Partner Working Meeting, University of Ottawa, ON, August 25, 2014, p. 5.

144. Nasser, N., Patterson, R.T., Macumber, A.L., Neville, L.A. Falck, H., Galloway, J.M., Kokelj, S.V., Roe, H.M. 2014. Arcellaceans (Testate Lobose Amoebae) As Proxies for Arsenic and Heavy Metal Contamination in the Baker Creek Watershed Region, Northwest Territories, Canada. Understanding the Nature, Extent and Fate of Legacy Contamination Near Yellowknife, NWT. Partner Working Meeting, University of Ottawa, ON, August 25, 2014, p. 8.

143. Roe, H.M., Patterson, R.T. 2014. Testate Amoebae (Arcellacea) as bio-indicators of road salt contamination in lakes 7th International Symposium on Testate Amoebae, Poznan, Poland, 8-12 September 2014, p. 19.

142. Crann, C., Patterson, R.T., Roe, H.M. 2014. Accumulation rate profiles for Arctic lakes, Canada. Radiocarbon in the Environment Conference Queen’s University Belfast, August 18-22 2014, p. 76

141. Nasser, N., Patterson, R.T., Macumber, A.L., Neville, L.A. Falck, H., Galloway, J.M., Kokelj, S.V., Roe, H.M. 2014. Arcellaceans (Testate Lobose Amoebae) As Proxies for Arsenic and Heavy Metal Contamination in the Baker Creek Watershed, Northwest Territories, Canada. Advances in Earth Sciences Research Conference (AESRC). Ottawa, Ontario. March.

2013

140. Patterson, R.T., Clark, I.A., Crann, C., Falck, H., Galloway, J.M., Gammon, P.R., Griffith, F., Macumber, A.L., Muise, P., Mullan, D.J., Pisaric, M.F.J., Prokoph, A., Roe, H.M., Sulphur, K.C., Swindles, G.T., Upiter, L.M., Vermaire, J.C., and Dalton, A.S., 2013. Paleoclimatological Assessment of the Central Northwest Territories and Implications for the Long- Term Viability of the Tibbitt to Contwoyto Winter Ice Road: A Project Overview 41st Annual Yellowknife Geoscience Forum Abstracts of Talks and Posters, Northwest Territories Geoscience Office, Yellowknife, NT, Irwin, D., (compiler), p. 48.

139. Falck. H., Galloway, J.M., Patterson, R.T., Roe, H.M., Palmer, M., Kokelj, S., Jamieson, H., 2013. Changing hydrology in the Taiga Shield: Geochemical and resource management implications Second NWT Environmental Monitoring Annual Results Workshop Yellowknife, Dec 2010-2012.

138. Trainor. P.G., Roe, H.M., Patterson, R.T., Dalton, A., Macumber, A.L., Griffith, F. 2013. ‘Investigating climate changes at the northwest Canadian tree-line: insights from a modern lake diatom dataset from the Northwest Territories’. British Diatomists’ Annual Meeting 2013. 25-27 Oct 2013. Blencathra, Cumbria.

137. Patterson, R.T., Crann, C., Macumber, A.L., Galloway, J.M., Roe, H.M., Patterson, R., and Falck, H., 2013. An 8,500 Year Holocene Paleolimnological Record from Frame Lake, Yellowknife, NT, 41st Annual Yellowknife Geoscience Forum Abstracts of Talks and Posters, Northwest Territories Geoscience Office, Yellowknife, NT, Irwin, D., (compiler), p. 79.

136. Galloway, J.M., Sulphur, K.C., Goldsmith, S.A., Trainor, P., Patterson, R.T., Hills, L.V., Roe, H.M., Swindles, G.T., Crann, C., Macumber, A.L., and Falck, 2013. H. Holocene Investigations of Three Lakes in the Central Northwest Territories: Climate Change across Ecotone Gradients and Implications for Future Change, 41st Annual Yellowknife Geoscience Forum Abstracts of Talks and Posters, Northwest Territories Geoscience Office, Yellowknife, NT, Irwin, D., (compiler), p. 22.

135. Griffith, F., Patterson, R.T., Clark, I., Macumber, A., Crann, C., and Dalton, A. A., 2013. High-Resolution Holocene and Recent Paleoclimate Reconstruction using C and N Isotopes, Northwest Territories, Canada, 41st Annual Yellowknife Geoscience Forum Abstracts of Talks and Posters, Northwest Territories Geoscience Office, Yellowknife, NT, Irwin, D., (compiler), p. 23.

134. Macumber, A.L., Patterson, R.T., Galloway, J.M., Falck, H., Swindles, G.T., and Crann, C., 2013. Lake Mud: A Tool to Identify Global Teleconnections and Quantify the Range of Environmental Responses to Climate Variability in the Northwest Territories, Canada 41st Annual Yellowknife Geoscience Forum Abstracts of Talks and Posters, Northwest Territories Geoscience Office, Yellowknife, NT, Irwin, D., (compiler), p. 41.

133. Nasser, N.A., Patterson, R.T., Neville, L.A., Macumber, A.L., Galloway, J.M., Falck, H., Roe, H.M., and Kokelj, S.V., 2013. Arcellaceans (Testate Lobose Amoebae) as Proxies for Arsenic and Heavy Metal Contamination in the Baker Creek Watershed, Northwest Territories, Canada. 41st Annual Yellowknife Geoscience Forum Abstracts of Talks and Posters, Northwest Territories Geoscience Office, Yellowknife, NT, Irwin, D., (compiler), p. 43.

132. Swindles, G.T., Mullan, D.J., Macumber, A., Galloway, J.M., Patterson, R.T., Crann, C., and Falck, H., 2013. The Tibbitt to Contwoyto Winter Road: Past and Future Climate Change, 41st Annual Yellowknife Geoscience Forum Abstracts of Talks and Posters, Northwest Territories Geoscience Office, Yellowknife, NT, Irwin, D., (compiler), p. 59.

131. Roe, H.M. and Patterson R.T., 2013. Arcellaceans (testate lobose amoebae) as bio-indicators of salt contamination in lakes: Insights from the Greater Toronto Region, Canada. The 32nd Meeting of the German Society for Protozoology, Kartause Ittingen CH-8532 Warth-Weiningen, Schweiz .Feb 27-Mar 2.

130. Crann, C., Patterson R.T., Macumber, A.L., Roe, H.M., Galloway, J.M., Falck, H., 2013. Spatial and temporal variability in lake accumulation rates in subarctic Canada: Implications for Bayesian age-depth modeling. Ontario – Quebec Paleolimnology Symposium (PALS) May 15-17, p. 21

129. Dalton, A.S., Macumber, A.L., Vermaire, J.C., Patterson, R.T., Crann C., Swindles, G.T.,
Galloway, J.M., Falck, H., 2013. Neoglacial Climate Variability in Diatom Populations from the sub-Arctic. Ontario – Quebec Paleolimnology Symposium (PALS) May 15-17, p. 23.

128. Macumber, A.L, Patterson, R.T., Dalton, A.S., Griffith, F., Swindles, G.T., Crann, C.,
Galloway, J.M., Neville, L.A., Falck, H., Climate Phenomena and Episodes Recorded in the Sediment Record from a Sub-Arctic Lake. Ontario – Quebec Paleolimnology Symposium (PALS) May 15-17, p. 23.

127. Nasser, N., Patterson, R.T., Falck, H, Galloway, J.M., Kokelj, S.V., Macumber, A.L., Crann, C., 2013. An assessment of Arsenic and heavy metal contamination and paleoclimatic change in Pocket Lake, Baker Creek Watershed, Northwest Territories, Canada. Ontario – Quebec Paleolimnology Symposium (PALS) May 15-17, p. 34.

126. Neville, L.A., Patterson, R.T., Gammon, P., Macumber, A.L., 2013. Arcellaceans (testate lobose amoebae) as an aquatic ecosystem bio-indicator to gauge the potential environmental impact of oil sands operations, specifically mercury in the Fort McMurray region, Alberta, Canada. Ontario – Quebec Paleolimnology Symposium (PALS) May 15-17, p. 37.

125. Babalola, L.O., Patterson, R.T., Prokoph, A., 2013. Foraminiferal evidence of a Late Holocene westward shift of the Aleutian Low pressure system. The 10th Meeting of the Saudi Society for Geosciences. King Fahd University of Petroleum and Minerals (KFUPM). April 15-17, 2013. Abstract SSG-10-163.

124. Crann, C., Patterson, R.T., Macumber, A.L., Roe, H.M., Galloway, J.M., Falck, H.,2013. Spatial and temporal variability in lake accumulation rates in subarctic Canada: insights from 22 dated lake records from the central Northwest Territories. Advances in Earth Sciences Research Conference (AESRC), London, Ontario March 22-24.

123. Patterson, R.T., Roe, H.M., Swindles, G.T. 2013. An Arcellacea (testate lobose amoebae/thecamoebian) based transfer function for phosphorus in lakes. “Protists as indicators of aquatic ecosystems health”: a workshop sponsored by the Hydrobiologie-Limnologie Stiftung für Gewässerforschung’. The 32nd Meeting of the German Society for Protozoology, Kartause Ittingen CH-8532 Warth-Weiningen, Schweiz.Feb 27-Mar 2.

2012

122. Neville, L.A., Gammon, P., Patterson, R.T., McCarthy, F.M.G., MacKinnon, M.D., Macumber. A. 2012. Responses of benthic microorganisms (thecamoebians) to Oil Sands Process-affected materials provide endpoints for gauging aquatic reclamation success International Oil Sands Tailings Conference Mayfield Inns and Suites, Edmonton, Alberta, Canada Abstracts Volume. December 2-5, p. 56

121. Dalton, A.S., Vermaire, J.C., Macumber, A.L., Patterson, R.T., Roe, H.M., Crann, C., Swindles, G.T., Galloway, J.M., Falck, H., 2012. Late Holocene cyclical patterns of diatom populations in sub-boreal Northwest Territorieis. 40^th Annual Yellowknife Geoscience Forum Abstracts of Talks and Posters, Northwest Territories Geoscience Office, Yellowknife, NT, Watson, D.M., (compiler), p. 7

120. Sulphur, K.C., Galloway, J.M. Hills, L.V., Crann, C., Macumber, A., Patterson, R.T., Falck, H. 2012. Palynological analysis of Danny’s Lake, Central Northwest Territories. 40^th Annual Yellowknife Geoscience Forum Abstracts of Talks and Posters, Northwest Territories Geoscience Office, Yellowknife, NT, Watson, D.M., (compiler), p. 70.

119. Patterson, R.T. 2012. Community structure dynamics and biodiversity across a continuum of past, present and future.International Paleolimnology Symposium Plenary Lecture.International Paleolimnology Symposium. Glasgow, Scotland, United Kingdom, SEEC 21-24 August. Abstracts Volume, p. 171 Key Note Lecture.

118. Macumber, A.L., Patterson, R.T., Galloway, J.M., Falck, H., Swindles, G.T., Crann, C., Neville, L.A., 2012. Understanding past environmental responses to cyclic climate phenomena in the Northwest Territories, Canada. International Paleolimnology Symposium. International Paleolimnology Symposium. Glasgow, Scotland, United Kingdom, SEEC 21-24 August. Abstracts Volume, p. 58

117. Dalton, A.S., Vermaire, J.C., Macumber, A.L., Patterson, R.T., Roe, H.M., Swindles, G.T., Trainor, P., Galloway, J.M., Falck, H., 2012. Diatoms as indicators of decadal to centennial-scale climate cyclicity and winter ice cover in the treeline regions of the central Northwest Territories, Canada. International Paleolimnology Symposium. Glasgow, Scotland, United Kingdom, SEEC 21-24 August. Abstracts Volume, p. 61.

116. Roe, H.M., Patterson, R.T. 2012. Examining benthic community response to road salt contamination in lakes: insights from a modern Arcellacea (testate lobose amoebae) dataset from southern Ontario, Canada. International Paleolimnology Symposium. International Paleolimnology Symposium. Glasgow, Scotland, United Kingdom, SEEC 21-24 August. Abstracts Volume, S14-P-08, p 179.

115. Griffith, F., Clark, I.D., Patterson, R.T., Macumber, A.L., Dalton, A.S., Crann, C., Trainor, P., Galloway, J.M., Falck, H. 2012.A reconstruction of climate history at high resolution using C and N isotopes, Northwest Territories, Canada. International Paleolimnology Symposium. Glasgow SEEC 21-24 August. Abstracts Volume, p. 26

114. Patterson, R.T., 2012. Paleoclimatological assessment of the central Northwest Territories, Canada: Implications for the long-term viability of the Tibbitt to Contwoyto winter Ice Road. Quaternary International v. 279, p. 369.

113. Crann, C., Patterson, R.T., Blaauw, M., Reimer, P.J., Roe, H.M., Macumber, A.L., 2012. Radiocarbon dating and Bayesian age-depth modeling in the Canadian subarctic (Tibbitt to Contwoyto Winter Road Project. International Paleolimnology Symposium. Glasgow, Scotland, United Kingdom, SEEC 21-24 August. Abstracts Volume, p. 74

112. Neville, L.A., Gammon, P., Patterson, R.T., Macumber, A. 2012. Arcellaceans (testate lobose amoebae) as an aquatic ecosystem bio-indicator to gauge the potential environmental impact of oil sands operations, Fort McMurray region, Alberta, Canada. International Paleolimnology Symposium. International Paleolimnology Symposium. Glasgow, Scotland, United Kingdom, SEEC 21-24 August. Abstracts Volume, S06-01, p. 81.

111. Crann, C.A., Patterson, R.T., Reimer, P.J., Griffith, F. 2012. Spatial and temporal variability of the old carbon effect in lacustrine sediments in a cold climate zone, Northwest Territories (Canada). UNESCO 21st International Radiocarbon Conference, Paris France, July 9-12, S06 p. 171

110. Neville, L.A., Gammon, P., Patterson, R.T., McCarthy, M.G., MacKinnon, M.D., Macumber, A. 2012. Use of an aquatic ecosystem bio-indicator to gauge environmental impact and efficiency of remediation efforts in oil sands tailings ponds and lakes surrounding Fort McMurray Alberta.Canadian Oil Sands Network for Research and Development, 2012 Water Conference and Workshops. 2012 Award for best student technical presentation (Poster).

109. Mertens, K.N, Bringué,, M., Van Nieuwenhove, N., Takano, Y., Pospelova, V.,Rochon, A., de Vernal, A., Taoufik, R., Dale, B., Patterson, R.T., Weckström, K., Andrén, E., Louwye, S., Matsuoka, K. 2012. Process length variation of the cyst of the dinoflagellate ‘Protoceratium reticulatum’ in the North Pacific: a new density proxy and first evidence of pseudo-cryptic speciation. IPC 2012, Tokyo.

108. Patterson, R.T., Roe, H.M. 2012. Development of a road salt contamination index utilizing thecamoebians (testate amoebae) Northeastern Section – 47th Annual Meeting, Hartford, CT, paper 47-8.

107. Roe, H.M., Patterson, R.T., 2012. Lake thecamoebians (testate amoebae) as indicators of watershed disturbance: case studies from the greater toronto area, ontario, canada Northeastern Section 47th Annual Meeting, Hartford, CT, paper 47-1.

2011

106. Neville, L.A., Macumber, A.L., Patterson, R.T., Galloway, J.M., Falck, H., Swindles, G.T. 2011. Temporal environmental proxies for assessing ‘problem’ lakes along the Tibbitt to Contwoyto Winter Road. In: Fischer, B.J., Watson, D.M. (compilers) 39th Annual Yellowknife Geoscience Forum Abstracts, Northwest Territories Geoscience Office, Yellowknife, NT, November 15-17, p. 111. 2011 Award for best student technical presentation (Poster).

105. Muise, P., Pisaric, M.F.J., Falck, H., Patterson, R.T. 2011. The dendroclimatic signal in white spruce rind widths along the Tibbitt to Conwoyto Ice Road, Yellowknife NWT. In: Fischer, B.J., Watson, D.M. (compilers) 39th Annual Yellowknife Geoscience Forum Abstracts, Northwest Territories Geoscience Office, Yellowknife, NT, November 15-17, p. 111.

104. Macumber, A.L., Neville, L.A., Patterson, R.T., Galloway, J.M., Falck, H., 2011. Characterization of lake types along the Tibbitt to Contwoyto Winter Road: The development of a preliminary thecamoebian-based transfer function to access climate change. In: Fischer, B.J., Watson, D.M. (compilers) 39th Annual Yellowknife Geoscience Forum Abstracts, Northwest Territories Geoscience Office, Yellowknife, NT, November 15-17, p. 110.

103. Griffith, F., Clark, I., Macumber, A.L., Patterson, R.T., Galloway, J.M., Falck, H. 2011. A high-resolution paleoclimatic reconstruction using bulk C and N isotope analysis of sediments from a subarctic lake northeast of Yellowknife, Northwest Territories, Canada. In: Fischer, B.J., Watson, D.M. (compilers) 39th Annual Yellowknife Geoscience Forum Abstracts, Northwest Territories Geoscience Office, Yellowknife, NT, November 15-17, p. 103.

102. Patterson, R.T., Clark, L.A., Crann, C., Falck, H., Galloway, J.M., Gammon, P.R., Griffith, F., Macumber, A.L., Muise, P., Neville, L.A., Pisaric, M.F.J., Prokoph, A., Roe, H.M., Swindles, G.T., Upiter, L., Vermaire, J.C. 2011. Paleoclimatic assessment of the central Northwest Territories, Canada: Implications for the long-term viability of the Tibbitt to Contwoyto Winter Road. In: Fischer, B.J., Watson, D.M. (compilers) 39th Annual Yellowknife Geoscience Forum Abstracts, Northwest Territories Geoscience Office, Yellowknife, NT, November 15-17, p. 58.

101. Goldsmith, S.A., Hills, L.V., Galloway, J.M., Macumber, A., Patterson,R.T., Falck, H. 2011. Late Holocene palynological investigation of Waite Lake, central Northwest Territories. In: Fischer, B.J., Watson, D.M. (compilers) 39th Annual Yellowknife Geoscience Forum Abstracts, Northwest Territories Geoscience Office, Yellowknife, NT, November 15-17, p. 103.

100. Macumber, A.L., Patterson, R.T., Galloway, J.M., Falck, H., Prokoph, A., Swindles, G.T., Neville, L.A. 2011. High resolution paleoclimatic reconstruction of lacustrine sediments from the Tibbitt to Contwoyto Winter Road, NWT, Canada. In: Fischer, B.J., Watson, D.M. (compilers) 39th Annual Yellowknife Geoscience Forum Abstracts, Northwest Territories Geoscience Office, Yellowknife, NT, November 15-17, p. 58.

99. Patterson, R.T., Galloway, J.M., Swindles, G.T., Prokoph, A., Macumber, A.L., Roe, H.M., Falck, H. 2011. Paleoclimatological assessment of the central Northwest Territories, Canada: Implications for the long-term viability of the Tibbett To Contwoyto Winter Ice Road. Session 19: Biotic proxies in lake sediments as quantitative indicators of Quaternary environmental change: development, calibration and applications. INQUA XVIII, Bern, Switzerland, July 21-27, 2011. pdf

98. Roe, H.M., Patterson, R.T., Swindles, G.T. 2011. Testate amoebae (thecamoebians) as water quality indicators in lakes: development of a modern distributional dataset from the Greater Toronto Area. Session 19: Biotic proxies in lake sediments as quantitative indicators of Quaternary environmental change: development, calibration and applications. INQUA XVIII, Bern, Switzerland, July 21-27, 2011.

97. Patterson, R.T., Babalola, L.O., Chang, A.S., Kumar, A., Prokoph, A., Roe, H.M., Vazquez-Riveiros, N., and Wigston, A.P., 2011, Linking solar forcing with climate and primary productivity changes in the Northeast Pacific: evidence from mid to late Holocene laminated sediments Geophysical Research Abstracts Vol. 13, EGU2011, Vienna, April 3-8.

96. Elliott, S.E., Roe, H.M., Patterson, R.T. 2011. Mid to late Holocene hydrological change in continental eastern Canada: assessing regional trends from ombrotrophic peat records. Geohydro 2011, 5 pp. Joint meeting of Canadian Quaternary Association and the Canadian chapter of the International Association of Hydrogeologists, 28-31 August 2011.

95. Roe, H.M., Patterson, R.T.. Swindles, G.S. 2011. Tracking catchment disturbance using lake thecameobians (testate amoebae): case studies from the Greater Toronto Area, Ontario, Canada. Geophysical Research Abstracts Vol. 13, EGU2011-12741, European Geophysical Union 2011, Vienna, April 3-8.

94. Elliott, S.E. Roe, H.M., & Patterson, RT. 2011. ‘Examining palaeo-hydrological transitions using testate amoebae and plant macrofossils: an 8,500 year record from Mer Bleue Bog, eastern Ontario, Canada’. QRA Annual Discussion Meeting, Liverpool, 4-6 Jan 2011.

93. Prokoph, A., Macumber, A.L., Patterson, R.T., Galloway, J.M. and Falck, H. 2011. Predictability of climate patterns in the central Northwest Territories: Implications for the long-term viability of the Tibbett to Contwoyto Winter Road. Symposium 1, Earth Climate: Past, Present, Future, Joint Geological Association of Canada – Mineralogical Association of Canada Annual Meeting, Ottawa, May 25-27.

92. El Bilali, H., and Patterson, R.T. 2011. Holocene climatic response to solar forcing: Evidence from the plant macrofossils δ18O cellulose record of Mer Bleue Bog, Ottawa, Ontario. Symposium 1, Earth Climate: Past, Present, Future, Joint Geological Association of Canada – Mineralogical Association of Canada Annual Meeting, Ottawa, May 25-27.

91. Patterson, R.T., Babalola, L.O., Chang, A.S., Kumar, A., Prokoph, A., Roe, H., Vazquez-Riveiros, N., Wigston, A., 2011. Influence of solar forcing on climate and primary productivity changes in the Northeast Pacific: Evidence from mid to late Holocene laminated sediments. Symposium 1, Earth Climate: Past, Present, Future, Joint Geological Association of Canada – Mineralogical Association of Canada Annual Meeting, Ottawa, May 25-27.

90. Benardout G., Patterson R.T.: Palaeoclimate reconstructions of the last 4000 years in the Southern Northwest territories using ostracods, and implications for the longterm viability of the Tibbitt to Contwoyto Winter Road. Abstracts of Scientific Contributions to 7th European Ostracodologists’ Meeting (EOM 7) and the 2nd Workshop “Methods in Ostracodology” (MIO 2). Joannea Geol. Paläont. 11: 21-24. Extended Abstract.

89. Babalola, L.O., Patterson, R.T., Prokoph, A., and Roe, H., 2011. Foraminiferal distribution in the Seymour Belize Inlet Complex, British Columbia: Implications for Holocene paleoceanographic reconstruction. Symposium 1, Earth Climate: Past, Present, Future, Joint Geological Association of Canada – Mineralogical Association of Canada Annual Meeting, Ottawa, May 25-27.

88. Macumber, A.L., Patterson, R.T., Galloway, J.M.,, Prokoph, A. and Falck, H., 2011. High resolution multiproxy study of lacustrine sediments from Waite Lake, Tibbitt to Contwoyto Winter Road, NT. Symposium 1, Earth Climate: Past, Present, Future, Joint Geological Association of Canada – Mineralogical Association of Canada Annual Meeting, Ottawa, May 25-27.

87. Babalola, L.O., Patterson, R.T., Prokoph, A., Swindles, G.T. and Kumar, A., 2011. A 1200-year record of paleoceaongraphic and paleoclimatic variability from the Seymour-Belize Inlet Complex, central coastal mountains region of British Columbia. Symposium 1, Earth Climate: Past, Present, Future, Joint Geological Association of Canada – Mineralogical Association of Canada Annual Meeting, Ottawa, May 25-27.

86. Neville, L.A., Macumber, A.L., Patterson, R.T., Michel, F., and Pisaric, M.F.J., 2011. Thecamoebians as an indicator of paleolimnologic change in meromictic Pink Lake, Gatineau Park, Quebec. Session GS6, Sedimentology, Joint Geological Association of Canada – Mineralogical Association of Canada Annual Meeting, Ottawa, May 25-27.

2010

85. Patterson, R.T., Galloway, J.M., Macumber, A.L., Falck, H., Madsen, E., Prokoph, A. 2010 Paleoclimatological Assessment Of The Central Northwest Territories: Implications For The Long-Term Viability Of The Tibbett To Contwoyto Winter Ice Road. 38th Annual Geoscience Forum, Yellowknife, Nov. 16-18. 2010.

84. Patterson, R.T., Macumber, A.L., Galloway, J.M., Falck, H., Hadlari, T., Neville, L.A., Roe, H.M., Swindles, G.T. 2010 Distribution And Environmental Significance Of Arcellacean (Thecamoebian) Assemblages From Lakes Along The Tibbitt To Contwoyto Winter Road, Northwest Territories, Canada. 38th Annual Geoscience Forum, Yellowknife, Nov. 16-18. 2010.

83. Pospelova, V., Price, A., Mertens, K., Chang, A., Patterson, R.T. 2010. British Columbia fjords, sediment traps, Operculodinium centrocarpum and a few other questions. (Palaeo)-ecology of cyst forming dinoflagellates. EUROPROX workshop/course on (Palaeo)-ecology of cycst forming dinoflagellates, Bremen, Germany, May 17-21, 2010. http://hdl.handle.net/1854/LU-2986934.

82. Macumber, A.L., Patterson, R.T., Galloway, J.M., Falck, H., Madsen, E., 2010. High Resolution Multiproxy Study Of Lacustrine Sediments From Waite Lake Along The Tibbitt Contwoyto Winter Road, Nwt, Canada. 38th Annual Geoscience Forum, Yellowknife, Nov. 16-18. 2010.

81. Babalola, L.O, Patterson, R.T. and Prokoph, A. 2010. Geochemical evidence for late Holocene Paleoclimatic and Paleoceanographic variability in Anoxic Basins, Seymour-Belize Inlet Complex, Central Coastal Mainland, British Columbia Geocanada 2010 Working With the Earth, Calgary, AB May 10-14, 2010.

2009

80. El Bilali, H., Patterson, R.T. 2009. Holocene Paleoclimate Reconstruction in Eastern Canada: Evidence from 18O of plant cellulose from the Mer Bleue Bog, Ottawa, Ontario. American Geophysical Union Annual Meeting, San Francisco, Dec 15. Paper Number: PP21D-07.

79. Patterson, R.T., Swindles, G.T., Roe, H.M. & 2009. Testate amoebae (Arcellacea) – based transfer function to infer past phosphorous concentrations in two agriculture impacted lakes. 11th International Paleolimnology Symposium, Guadalajara, Mexico, 15-18 Dec 2009.

78. Roe, H.M. Patterson, R.T., Swindles, G.T. 2009. Development of a thecamoebian (testate amoebae)-based transfer function to model phosphorus from lake sediments. 11th International Paleolimnology Symposium, Guadalajara, Mexico, 15-18 Dec 2009.

77. Roe, H.M. Patterson, R.T., Swindles, G.T. 2009. Controls on the distribution of lake thecamoebians (testate amoebae) in the Greater Toronto area and their potential as water quality indicators. Fifth International Sypmosium on testate amoebae (ISTA5). Montbéliard, France. 14-17 Sept 2009.

76. Babalola, L.O., Patterson, R.T., Prokoph, A. 2009. Geochemical evidence for late Holocene multi-decadal-centennial paleoclimatic and paleoceanographic variability in an anoxic basin, coastal British Columbia. Geological Society of America Annual Meeting Abstrctst with Programs, v 41, No. 7, p. 514. 2009 Portland GSA Annual Meeting (18-21 October 2009). https://gsa.confex.com/gsa/2009AM/finalprogram/abstract_160498.htm

2007

75. Patterson, R.T., Prokoph, A., Chang. A., Roe, H.M., Vazquez-Riveiros, N., Wigston, N. 2007. A possible cosmoclimatological driver of observed cyclic holocene climate change and marine productivity in the northeastern Pacific. Pacific Climate Workshop, May 13-16, 2007, Asilomar State Conference Grounds, Pacific Grove, CA

74. Roe, H.M., Doherty, C.T., Patterson, R.T., Milne, G.M. 2007. Postglacial relative sea-level and climatic history of the Seymour-Belize Inlet Complex, British Columbia: biostratigraphic evidence from isolation basins. Pacific Climate Workshop, May 13-16, 2007, Asilomar State Conference Grounds, Pacific Grove, CA

73. Kumar, A., Swindles, G.T., Patterson, R.T., Roe, H.M. (2007). ‘Late Holocene paleoceanography of Effingham Inlet, Vancouver Island, Canada, using dinoflagellate cyst assemblages’. American Association of Stratigraphic Palynologist (AASP) Annual Meeting, Panama, 8-12 Sept 2007.

2006

72. Patterson, R.T. 2006. Utility of Online Asynchronous Tutorial Discussion Groups in Large Undergraduate Courses, EOSET, Carleton University, Feb 21.

70. Patterson, R.T., Chang, A., Galloway, J.M., Kumar, A., Prokoph, A., Reinhardt, E.G., Roe, H.M., Vazquez Riveiros, N., Wigston, A. 2006. Celestial forcing as a possible driver of cyclic Holocene climate and marine productivity in the NE Pacific. Session 130 – Quaternary Micropaleontology: Quantifying Environmental Change. Geological Society of America Annual Meeting Abstracts with Programs, v. 38, no. 7 (Oct 22-25), p. 323. Paper No. 130-7 Philadelphia Convention Center: 204C, 9:40AM Tuesday 24 October 2006. https://gsa.confex.com/gsa/2006AM/finalprogram/abstract_114198.htm

2005

69. Chang, A.S. and Patterson, R.T. 2005. Mid-Holocene climate shift: An analogy for modern change? 4th NCCR Climate Summer School. Universität Bern. Grindelwald, Switzerland; 28 Augustˆ2 September. [Poster].

68. Patterson, R.T., Prokoph, A., Kumar, A., Chang, S. and Roe, H. 2005. The sun as a driver of climate and marine productivity in the NE Pacific. Quaternary Ocean and Land Interaction: Climatic, tectonic and anthropogenic influence, Anyer-Carita, Banten-Sunda Straint Area, A joint INQUA – IGCP 495 Meeting Sept. 24-30, 2005.

67. Chang, A.S., Patterson, R.T., Prokoph, A., & Roe, H.M. 2005. ‘Solar Influence on climate and diatoms in the Northeast Pacific’. North American Micropaleontology Section (NAMS) of SEPM (Society for Sedimentary Geology) Annual meeting, Geologic Problem Solving with Microfossils, Rice University, Houston, Texas, USA, March 6-11, 2005, p. 44.

66. Patterson, R.T. 2005. Climate Change: A scientific perspective. Keynote speaker. IEEE Sponsored Kyoto and Climate Change Technology Challenges and Opportunities Seminar, Ottawa, May 13, 2005.

65. Patterson, R.T., Dalby, A.P. & Roe, H.M. 2005. ‘Salt marsh foraminifera as sea-level indicators in New Brunswick and British Columbia: a quantitative approach to assessing regional variability in taphonomic biasing and preferred faunal habitat’. North American Micropaleontology Section (NAMS) of SEPM (Society for Sedimentary Geology) Annual meeting,Geologic Problem Solving with Microfossils, Rice University, Houston, Texas, USA, March 6-11, 2005, Abstract vol p. 45.

2004

64. Patterson, R.T. 2004 Possible solar influence on climate and marine productivitiy: a fishy story. Invited speaker. Logan Club Lecture Series, Geological Survey of Canada, Ottawa. Dec. 9, 2004.

63. Roe, H.M., Patterson, R.T. 2004. ‘The impact of land-use change on water quality and management in the Oak Ridges Moraine, southern Ontario: some perspectives from the recent historical past’. The Canadian Association of Geographers, Annual Meeting, Moncton, New Brunswick, 25-29 May 2004. Abstracts Volume. p. 136.

2003

62. Galloway, J.M, Doherty, C.T., Roe, H.M., and Patterson, R.T., 2003. A pollen and diatom based reconstruction of Holocene paleoclimate at Two Frog Lake, coastal British Columbia, Canada. Joint AASP/CAP/NAMS Meeting Niagara, October 5-8, 2003

61. Patterson, R.T., Prokoph, A., Kumar, A., and Chang, A. 2003. Influence of solar variability on Holocene pelagic fish and phytoplankton productivity in the NE Pacific Ocean. Joint AASP/CAP/NAMS Meeting Niagara, October 5-8, 2003

60. Galloway, J.M., Boudreau, R.E.A., Michel, F.A., and Patterson, R.T., 2003. A palynological reconstruction of holocene climate at james lake, north-eastern Ontario. 36th Annual Meeting of the American Association of Stratigraphic Palynologists: Joint Meeting With the Canadian Association of Palynologists and the North American Micropaleontology Section, SEPM, Program with Abstracts, St. Catharines, Ontario, Canada, Oct 5-8, 2003.

59. Galloway, J.M, Doherty, C.T., Roe, H.M., and Patterson, R.T., 2003. A pollen and diatom based reconstruction of Holocene paleoclimate at two frog lake, coastal British Columbia, Canada. 36th Annual Meeting of the American Association of Stratigraphic Palynologists: Joint Meeting With the Canadian Association of Palynologists and the North American Micropaleontology Section, SEPM, Program with Abstracts, St. Catharines, Ontario, Canada, Oct 5-8, 2003.

58. Patterson, R.T., Prokoph, A., Kumar, A., and Chang, A. 2003. Influence of solar variability on Holocene pelagic fish and phytoplankton productivity in the NE Pacific Ocean. 36th Annual Meeting of the American Association of Stratigraphic Palynologists: Joint Meeting With the Canadian Association of Palynologists and the North American Micropaleontology Section, SEPM, Program with Abstracts, St. Catharines, Ontario, Canada, Oct 5-8, 2003.

57. Patterson, R.T., Fowler, A.D., and Huber, B.T. 2003, Hierarchical Organization in the Planktic Foraminiferal Evolutionary Record. 36th Annual Meeting of the American Association of Stratigraphic Palynologists: Joint Meeting With the Canadian Association of Palynologists and the North American Micropaleontology Section, SEPM, Program with Abstracts, St. Catharines, Ontario, Canada, Oct 5-8, 2003.

56. Doherty C., Roe H.M., Patterson T. 2003. Isolation basin stratigraphy and Holocene relative sea-level change in Seymour Inlet, central British Columbia, Canada. IGCP 437 Annual Meeting, Puglia, Italy, Quaternary coastal morphology and sea level changes Sept 22-28, 2003.

2002

55. Patterson, R.T., Gehrels, W.R., Belknap, D.F., Dalby, A.P., 2002. Possible influence of cold winter temperatures on taphonomic biasing of marsh foraminiferal faunas: implications for surface sampling strategies in paleo-sea level reconstruction. IGCP Project 437 International Conference on Quaternary Sea Level Change, Barbados, Oct 26-Nov. 2, 2002, Abstracts Volume.

54. Chang, A.D., Hay, M.B., Prokoph, A., and Patterson, R.T., 2002. High resolution diatom productivity and cyclostratigraphy (1947-1993) from Effingham Inlet, British Columbia, Canada (P31). 17th International Diatom Symposium Ottawa, Canada, 25-31 August 2002 Program, p. 15.

53. Dallimore, A., Barrie, J.V., Patterson R.T., Thomson, R.E., Reinhardt, E.G. and Roe, H.M., 2002. A high-resolution Holocene paleoclimatic, paleoceanographic and sea level record from anoxic basins and coastal lakes of the British Columbia coast. IGCP Project 437 International Conference on Quaternary Sea Level Change, Barbados, Oct 26-Nov. 2, 2002, Abstracts Volume.

2001

52. Patterson, R.T., Prokoph, A., Dallimore, A., Thomson, R.E., Ware, D.M., Wright, C. 2001. Impact of abrupt Holocene climate changes and solar cyclicity on fish population dynamics in the NE Pacific. Paper #25609 Geological Society of American Annual Meeting November 5-8, 2001 Boston, Massachusetts, USA

51. Patterson, R.T., and Clague, J.J. (September, 2001). Marsh foraminiferal evidence of coseismic subsidence north of the Nootka fault during the AD 1700 Cascadia megathrust earthquake The 3rd International Conference of the International Geological Correlation Programme Project No. 437 In association with the INQUA NEOTECTONICS Commission. Conference Theme: ‘Sea-level changes and neotectonics’ Durham and Fort Willaim , Scotland, UK, 4th to 12th September 2001. Oranized by Ian Shennan, Ben Horton, and Niamh EmElherron, University of Durham.

50. Dallimore, A., Patterson, R.T. and Thomson, R.E. (September, 2001) Discrimination of oxygenation episodes from earthquake events in late Holocene sediments of Anoxic Effingham Inlet, Vancouver Island, British Columbia. The 3rd International Conference of the International Geological Correlation Programme Project No. 437 In association with the INQUA NEOTECTONICS Commission. Conference Theme: ‘Sea-level changes and neotectonics’ Durham and Fort Willaim , Scotland, UK, 4th to 12th September 2001. Oranized by Ian Shennan, Ben Horton, and Niamh EmElherron, University of Durham.

49. Patterson, R.T. (invited paper) February 21, 2001) Assign,ment of World Wide Web Virtual Museum Projects in Undergraduate Courses, Educ@tional Technology Conference, Carleton University, Wednesday, February 21, 2001.

2000

48. Kumar, A., and Patterson, R.T., 2000. Distribution of palynomorphs in the bottom sediments of Effingham Inlet, Vancouver Island on the Pacific coast of Canada. The second International Conference “Application of Micro- and Meioorganisms to Environmental Problems” Winnipeg, Manitoba, Canada, August 27-Sept 1., 2000. Program and Abstracts p. 69-70.

47. Prokoph, A., Fowler, A.D., and Patterson, R.T. 2000. Characterization of Morphology by 2-Dimensional wavelet analysis: planktic foraminifera as a case study: Session TS-36 Visualization in Geoscience: Objects and Processes. Geoscience 2000, May 29-June 2, Calgary, Abstracts with Program, Abstract 461.

46. Kumar, A., and Patterson, R.T. Arcellaceans (thecamoebians) as proxies of chemical pollution and remediation in lakes Palynology and micropaleontology in Canadian Geoscience: New frontiers and applications, Geoscience 2000, May 29-June 2, Calgary, Abstracts with Program, Abstract 1134.

1999

45. Prokoph, A., Fowler, A.D., and Patterson, R.T. 1999 Cycles, events and self-organization in the planktic foraminifera extinction record from the last 125Myr. GAC/MAC Annual Meeting, Quebec City, v. 24, May.

44. McGowan, A.J., Pearson, P.N., Stearn, C.W., Patterson, R.T. 1999. ADAPTS (analysis of diversity, asymmetry of phylogenetic trees, and survivorship): a new software tool for analysing stratigraphic range data. Paleontological Society theme session T-39.

1998

43. Kumar, A., and Patterson, R.T. (October, 1998) Foraminiferal Analysis of the Cores From ODP Site 1033B (Leg 169S), Saanich Inlet, British Columbia: Evidence For Subaqueous Debris Flows. Geological Society of America Annual Meeting, Toronto, Ontario, October 25-29, 1998.

42. Patterson, R.T. (Invited paper, October, 1998) Palaeontologia Electronica: A Timely New Publication Medium Geological Society of America Annual Meeting, Toronto, Ontario, October 25-29, 1998.

41. Patterson, R.T. (Invited paper, October, 1998) Beyond the cutting edge: electronic publication in the 21st century. Geoscience Information Society, Digital Database Forum. Toronto Convention Centre, Oct 25, 1998.

40. Dalby, A.P.; Kumar, A., Moore, J.M, and Patterson, R.T., GSA (Oct., 1998) Assessment Of Arcellaceans (Thecamoebians) As Limnological Indicators In Tropical Lake Sentani, Irian Jaya, Indonesia, Geological Society of America Annual Meeting, Toronto, Ontario, October 25-29, 1998.

39. Patterson, R.T., Dalby, A.P., Hutchinson, I., Guilbault, J.-P., and Clague, J.J. (September, 1998) Vertical Zonation Of Diatom, Foraminifera, And Macrophyte Assemblages In A Coastal British Columbia, Canada Marsh: Implications For Greater Paleo-Sea Level Resolution. UNESCO-IUGS IGCP 367, INQUA Shorelines Commission, INQUA Neotectonics Commission joint meeting on Rapid Coastal Changes in the Late Quaternary: Processes, causes, modelling, impacts on coastal zones, Corinth and Samos, Greece, 10-19 September 1998, p. 45.

38. Reinhardt, E.G., Stanley, D., and Patterson, R.T. Strontium Isotopic-Paleontological Method as a High Resolution Paleosalinity tool for Nile Delta Lagoons. World Deltas Symposium, New Orleans, Lousiana, USA, August 23-29, 1998.

37. Boudreau, R.E.A., Patterson, R.T., Dalby, A.P., and McKillop, W.B. (Oct. 1998) Mid Continent Non-Marine Occurrence of Live Cribroelphidium gunteri, a Marine Foraminifera, Abundant in Lake Winnipegosis, Manitoba. Geological Society of America Annual Meeting, Toronto, Ontario, October 25-29, 1998.

36. Kumar, A., Patterson, R. T. (May, 1998) Allochthonous Foraminifera as Evidence of Subaqueous Debris Flows from ODP Site 1033 B (Leg 169 S), Saanich Inlet, British Columbia GAC/MAC Annual Meeting, Quebec City, v. 23, (abstract #525)

35. Dalby, A.P., Bagi, H., Boudreau, R.E.A., Henderson, L.A., Kumar, A., Anderson, T.W, and Patterson, R.T. 1998. Arcellaceans (Thecamoebians) as Paleolimnological Proxies; Latest Pleistocene-Recent Record from Swan Lake, North of Toronto, Ontario. GAC/MAC Annual Meeting, Quebec City, v. 23. May

1997

34. Patterson, R.T., Kumar, A., and Dumaresq, C, (October, 1997). Arcellaceans: shelled microinvertebrates as cost-effective tools for monitoring current and historical environmental trends. 24th Annual Aquatic Toxicity Workshop, Niagara Falls, Ontario, October 19-22, 1997.

33. Reinhardt, E.G., Patterson, R.T. and Scott, D.B. (Dec. 1997) Unraveling the History of an Ancient Harbor from Southern Oman; Sedimentological and Micropaleontological Evidence. Neotectonics, Coastal Archaeology and Sea-Level Variations, American Geophysical Union 1997 Fall Meeting. San Francisco, CA, USA.

32. Reinhardt, E.G., and Patterson, R.T., (Invited paper, June, 1997) Sedimentological Analysis and Stratigraphic Interpretation of the Ancient Outer Harbor at Caesarea. The 9th Symposium on the Continental Margins of Israel. Israel National Oceanographic Institute, Haifa, Israel.

31. Reinhardt, E.G., Patterson, R.T., and Scott, D.B. (Invited Plenary Lecture June, 1997) Foraminifera as a Paleoenvironmental Proxy in Marine Archaeology. The First International Conference “Application of Micropaleontology in Environmental Sciences”. Porter Super-Center for Ecological and Environmental Studies and the Institute for Nature Conservation Research, Tel Aviv University. Tel Aviv, Israel June 15-20, 1997.

30. Patterson, R.T. (May, 1997) Significance of marsh foraminiferal infaunal habitat and taphonomic processes for high-resolution sea-level studies. 1997 GAC/MAC Annual Meeting, Ottawa, v. 22, p. A-113.

29. Reinhardt, E.G., Patterson, R.T., Blenkinsop, J., Raban, A. (May, 1997) A combined micropaleontological/strontium isotopic methodology as a paleosalinity indicator: evidence from King Herod the Great’s Harbor, Caesarea Maritima, Israel. 1997 GAC/MAC Annual Meeting, Ottawa, v. 22, p. A-124.

28. Kumar, A., Patterson, R.T. (May, 1997) Arcellaceans (Thecamoebians) as proxies of lake bottom acidity: an example from James Lake, Northeastern Ontario. 1997 GAC/MAC Annual Meeting, Ottawa, v. 22, p. A-150.

27. Dalby, A.P., Patterson, R.T., Haggart, J.W. (May, 1997) Cretaceous foraminifera from the Queen Charlotte Islands, British columbia, Canada. 1997 GAC/MAC Annual Meeting, Ottawa, v. 22, p. A-34.

1996

26. Patterson, R.T., Guilbault, J.-P., and Clague, J.J. (November, 1996). Marsh foraminiferal infaunal habitat and taphonomic processes: significance for high-resolution sea-level studies. IGCP 367 – Late Quaternary Evidence of Rapid Sea-Level Change Annual Meeting, Sydney Australia.

25. Reinhardt, E.G., Patterson, R.T., (Nov. 1996) Neotectonic Subsidence of Herod the Great’s Harbour: the Last Paroxysm. IGCP Project 367 – Late Quaternary Coastal Records of Rapid Change: Application to Present and Future Conditions. III Annual Meeting Sydney, Australia.

1995

24. Patterson, R.T., Ozarko, D., and Clague, J.J. (Invited paper, Oct.,1995). Implications of marsh foraminiferal infaunal habit and taphonomic processes for sea-level studies. Geological Society of America, Abstracts with Programs, v. 27, no. 6, p. A28.
Reinhardt, E.G., Patterson, R.T., Easton, N.A., (Aug. 1995) Late Holocene Sea Level Change and Amerindian Site Distribution at Montague Harbour, British Columbia; Foraminiferal and Sedimentological Evidence. Linkages to Late Quaternary Sea Level and Geoarchaeology, The 1st SEPM Congress on Sedimentary Geology “Linked Earth Systems” St. Pete Beach FL.

23. Patterson, R.T. and Fowler, A.D., (Invited Paper, August,1995). Evidence of determinism in planktic foraminiferal evolution: implications for interconnectedness of paleoecosystems. Society of Economic Paleontologists and Mineralogists Annual Meeting, Linkages to Late Quaternary Sea Level and Geoarchaeology, The 1st SEPM Congress on Sedimentary Geology “Linked Earth Systems” St. Pete Beach FL.

22. Cavazza, W., Patterson, R.T., Reinhardt, E.G., and Blenkinsop, J., (April,1995). Paleoclimatic-Paleoceanographic Changes And The Strontium Isotopic Record. European Union of Geosciences, Strasbourg, France, April 1995.

21. Patterson, R.T., (February,1995). Use of marsh foraminifera to recognize coseismic sea level changes on Lower Mainland and Vancouver Island, British Columbia. Cordilleran Workshop, February 10-12, 1995 Department of Earth Sciences, Carleton University.
Patterson, R.T., Blenkinsop, J., Reinhardt, E.G., and Cavazza, W., (Invited paper, March, 1995). Integrated Micropaleontological/Geochemical (87Sr/86Sr) Approach to Obtaining Refined Age Control in Fossil Poor sedimentary Sequences: The Oligocene-to-Pleistocene Calabria-Peloritani Arc, southern Italy as a case study. American Association of Petroleum Geologists Annual Meeting, Houston Texas, March 508, 1995, v. 4, p. 74-75

1994

20. Patterson, R.T., Ozarko, D.L., Guilbault, J.-P., and Clague, J.J., (Invited paper, Oct.,1994). Distribution and preservation potential of marsh foraminiferal biofacies from the lower mainland and Vancouver Island, British Columbia. Geological Society of America Annual Meeting, Seattle, Washington, October 24-27, v. 26, no. 7, p. 530.

19. Blenkinsop, J., Cavazza, W., Patterson, R.T., and Reinhardt, E.D., (June,1994). Observed 87Sr/86Sr Isotopic variation in pelagic mudrocks of Pliocene age are the results of orbitally forced periodic variation in continental runoff. Eighth International Conference on Geochronology (ICOG), June 1994, Berkeley, CA.

18. Blais, A. and Patterson, R.T. (October,1994). Foraminiferal biofacies of Saanich Inlet, Vancouver Island, British Columbia: valuable environmental indicators. Geological Society of America Annual Meeting, Seattle, Washington, October 24-27, v. 26, no. 7, p. A 345.
Burbidge, S.M. and Patterson, R.T. (October,1994). Holocene Arcellacea (Thecamoebians) as paleolimnological indicators in several small lakes from southwestern New Brunswick. Geological Society of America Annual Meeting, Seattle, Washington, October 24-27, v. 26, no. 7, p. A 344.

17. Scott, D.B., Collins, E.S., Duggan, J., Jennings, A., Patterson, R.T., Asioli, A., and Nelson, A.R. (October,1994). Modern Pacific coast marsh foraminiferal zonations: comparison with Atlantic coast associations. Geological Society of America Annual Meeting, Seattle, Washington, October 24-27, v. 26, no. 7, p. 531.

16. Reinhardt, E.G., Patterson, R.T., Schröder-Adams, C. J. (Oct. 1994) The Paleoecology of Benthic Foraminifera and Marine Archaeology: A Case Study from the Ancient Harbor of Caesarea Maritima, Israel: Science and Archaeology: Towards an Interdisciplinary Approach to Studying the Past. Harvard University, Boston, MA. October 14-16, 1994.

1993

15. Reinhardt, E.G., Patterson, R.T., and Schröder-Adams, C.J., (Dec. 1993) Sedimentological History of the Ancient Harbor Site of Caesarea Maritima, Israel using Benthic Foraminifera as an Archaeological Indicator. Archaeological Institute of America Annual Meeting. Washington D.C.

14. Reinhardt, E.D., Patterson, R.T., Schroeder-Adams, C.J., and Buyce, M. R., (Oct. 1993) Geoarchaeology of the ancient harbor site of Caesarea Maritima, Israel: evidence of its creation and destruction from sedimentology and micropaleontology. Geological Society of America Annual Meeting, Boston, October, 1993. (Selected as a press release for the conference, only 5% are chosen from all the papers submitted).

13. Patterson, R. T., Cavazza, W., and Blenkinsop, J., (April,1993). Planktic foraminiferal biostratigraphy and 87Sr/86Sr Isotopic stratigraphy of the Oligocene-to-Quaternary sedimentary sequence in the southern Calabrian-Peloritani Arc, southern Italy. 14th Regional Meeting of the International Association of Sedimentologists, Marrakesh, Morocco, April, 1993, Abstract Volume, p. 258.

1992

12. Mathewes, R.W., Heusser, L.E., and Patterson, R.T., (September,1992). Paleoecological evidence for a Younger Dryas event in western Canada. Symposium of the “Global Younger Dryas” at the 8th International Palynological Congress in Aix-en-Provence, France, September, 1992.

11. Mathewes, R.W., Heusser, L., and Patterson, R.T., (May,1992) “Paleoecological Evidence for a Younger Dryas Event in Western Canada”. Mineralogical Association of Canada Joint Annual Meeting, Wolfville, N.S. May 16-18, 1992.

1991

10. Patterson, R.T., Mathewes, R.W., and Heusser, L.E., (October, 1991). Foraminiferal and pollen evidence of late Quaternary cooling on the British Columbia coast – a possible Younger Dryas Event. Geological Society of America Annual Meeting, San Diego, October 20-24, 1991. (Selected as a press release for the conference, only 5% are chosen from all the papers).

9. Clark, F.E. and Patterson, R.T., (October,1991) Distribution of Holocene benthic foraminifera and associated water masses, tropical southwest Pacific Ocean. Geological Society of America Annual Meeting, San Diego, October 20-24, 1991.

1990

8. Patterson, R.T., 1990. (October, 1990) Later Quaternary distribution and paleoecological importance of benthic foraminiferal biofacies from Queen Charlotte Sound and Southern Hecate Strait, British Columbia. Geological Society of America Annual Meeting, Dallas, October 29-November 1, 1990.

7. Burbidge, S.M. and Patterson, R.T., (November, 1990) Foraminiferal assemblages of the Late Pleistocene Lake Champlain sediments of Ottawa, Canada. Geological Society of America Annual Meeting, Dallas, October 29 – November 1, 1990.

6. Patterson, R.T. and Cameron, B.E.B., ( May,1990). Depositional environment of two Late Quaternary cores bearing foraminifera and ostracodes from the Fraser Delta, British Columbia. Geological Association of Canada – Mineralogical Association of Canada Joint Annual Meeting, Vancouver, May 16-18, 1990.

5. Patterson, R.T., (May,1990). Paleoecological Significance of foraminifera biofacies from Recent tidal flats and fringing marshes of the Fraser River Delta, British Columbia. Geological Association of Canada – Mineralogical Association of Canada Joint Annual Meeting, Vancouver, May 16-18, 1990.

1989

4. Patterson, R.T. (September, 1989) Paleoenvironmental significance of intertidal benthic foraminiferal biofacies from the Fraser River Delta, British Columbia, Canada: International Advanced Course on Paleoecology, Biostratigraphy, Paleoceanography, and Taxonomy of Agglutinated Foraminifera: NATO Advanced Study Institutes Programme, Tübingen, West Germany, 17-28 September, 1989.

3. Yeh, C.C., Patterson, R.T., and Osborne, R.H., (May, 1989) Fourier shape analysis of the planktonic foraminifer Neogloboquadrina pachyderma (Ehrenberg) from the Santa Barbara Formation, California: Geological Society of America Cordilleran and Rocky Mountain Sections Annual Meeting, May 8-10, Spokane, Washington: Contribution #20301.

1985

2. Patterson, R.T. (February, 1985) Foraminifera from two cores collected in Barataria Basin, Louisiana. University of California Paleontology Conference, Bodega Marine Laboratory, Bodega Bay, California, February, 23-24, 1985, p. A6

1. Patterson, R.T. and Pettis, R.H. (February, 1985) A Taxonomic Revision of the Unilocular Foraminifera. University of California Paleontology Conference, Bodega Marine Laboratory, Bodega Bay, California, February, 23-24, 1985, p. A6.

Share: Twitter, Facebook
Short URL: https://carleton.ca/timpatterson/?p=651