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Palynological study of the continental shelf sediments of the Labrador Sea

University of British Columbia

A detailed palynological examination was made of Tertiary pollen and spore assemblages from six exploratory wells located along the continental margins of the Labrador Sea. From north to south, the study wells are Kangamiut 1, Hekja 0-71, Karlsefni A-13, Herjolf M-92, Roberval K-92 and Cartier D-70. Using local extinction events of zonally diagnostic species to define the tops of intervals, eight provisional pollen and spore zones were established. The zones and their relative ages are as follows: Tsuga igniculus (middle to late Miocene); Fagus granulata (early to middle Miocene); Parviprojectus sp. A (early Oligocene); Araliaceoipollenites megaporifer (latest Eocene/earliest Oligocene); Rhoipites latus (middle to late Eocene); Pistillipollenites mcgregorii (early to middle Eocene); Tricolpites sp. A (middle to late Paleocene); and Paraalnipollenites alterniporus (early to middle Paleocene). The middle and upper Oligocene is apparently absent in the study welIs. When used in conjunction with dinoflagellate assemblages, the zonation provides the potential for additional biostratigraphic resolution in the Tertiary marine sediments of the Labrador Sea. It is especially useful in upper Eocene and stratigraphically higher sections in which pollen and spores are the dominant component of the palynoflora: In addition, the basic similarity of pollen and spore assemblages across much of northern and western Canada suggests the zonation may also be successfully applied in those regions. The relative abundance and distribution of four major populations (i.e., Paleozoic, Upper Jurassic/Lower Cretaceous, Upper Cretaceous and Paleogene) of redeposited palynomorphs were determined. The species composition of recycled and in-situ Paleogene palynomorphs supports independent clay mineralogical data that much of the sediment (including a high percentage of the palynomorphs) was delivered to offshore Labrador Sea basins via a "super" river system that drained a large portion of the western interior and Arctic regions of Canada during the Tertiary. The taxonomic composition of the indigenous Paleogene pollen and spore flora supports both paleontological and isotope data that relatively high paleotemperatures prevailed at high northern latitudes during the Paleogene. The climatic optimum in the Labrador Sea region was reached in the early to early-middle Eocene.

Thesis/Dissertation

eng

Vancouver : University of British Columbia Library

10.14288/1.0052419

Doctor of Philosophy - PhD

Science, Faculty of; Earth, Ocean and Atmospheric Sciences, Department of

UBCV

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