Patterson, R.T., 1993. Late Quaternary benthic foraminiferal biofacies and paleoceanography of Queen Charlotte sound and southern Hecate Strait, British Columbia. Journal of Foraminiferal Research, 23:1-18.
A high resolution analysis was carried out on the foraminiferal faunas from the 13,000 ? 9000 years B.P. piston core END 84B-10 from Goose Island Trough, Queen Charlotte Sound, on the British Columbia shelf. Cluster analysis of the data resulted in the recognition of five separate faunas related to distinct paleoceanographic phases during the late Quaternary history of the site. In particular, these results provide detailed information on the paleoceanographic conditions that prevailed in the area: (1) during passage of a late Quaternary glacial forebulge across the region; and (2) during development and waning of the west coast Younger Dryas?like isochronous cooling event.
Passage of the glacial forebulge across this core site (beginning 11,470-11,260 years B.P. and terminating prior to 10,000 years B.P.) resulted in a gradual decrease in water depth to 70?85 m, based on sedimentological data and increasing proportions of Buliminella elegantissima. In the early stages of the regression circulation remained open and salinity at near normal marine levels despite the emergence of a number of nearby large islands, as indicated by the high Shannon?Weiner diversity indexes (up to 2.5), the high proportion of planktic foraminifera, and the presence of deep shelf phenotypes of Cribroelphidium hallandence. However, the continued emergence of nearby islands began to constrict local waterways, as suggested by the fall in the proportion of planktic foraminifera from 11.8 to 2.6% over the course of the regression.
Near glacial conditions between 11,260 ? 10,000 years B.P. at this locality are unrelated to passage of the glacial forebulge. The inundation of very cold water over the area is evidenced by the presence of high proportions of Cassidulina reniforme and Cassidulina helenae. Abundant Cassidulina helenae is also indicative of depressed salinities The presence of some temperate species provides evidence that any local glacial advances were restricted to coastal fjords, some distance away. The observed depressed salinity and temperature regime may have resulted from a slight modification of existing regional seasonal weather patterns associated with the hemispheric, or global, climatic changes accompanying the Younger Dryas cooling event. Decreased mean continental summer temperatures could have resulted in a reduced influence of the North Pacific High and a lengthening of the seasonal influence of the Aleutian Low. Oceanographically this would have resulted in a near continuous onshore Ekman flow and resultant downwelling, carrying cold, low salinity surface plumes to depth.
By 10,000 years B.P. the west coast Younger Dryas?like cooling event had terminated and weather and oceanographic circulation had returned to near modern patterns as indicated by the near replacement of Cassidulina helenae by Nonionellina labradorica and the development of a modern shelf Epistominella vitrea dominated biofacies.