Evidence for a Late Quaternary outburst flood event in the Georgia Basin, British Columbia

Coring of Late Quaternary sediments in the Georgia Basin has revealed stratigraphic and micropaleontological evidence of an outburst flood that deposited a clay layer over much of the seafloor of the Strait of Georgia. The flood originated in the Fraser Valley or the British Columbia interior during deglaciation when an ice-dammed lake or lakes drained catastrophically. A reworked pollen assemblage contained within the clay unit has a source in the Fraser Valley or the British Columbia interior. The clay unit contains a characteristic grain-size signature, sedimentary structures, and a radiocarbon chronology consistent with a rapidly deposited unit emplaced by a flood event. Diatom assemblages show that a markedly lower salinity of surface waters accompanied deposition. Radiocarbon dating indicates that the flood occurred between 9160 and 9800 radiocarbon years BP. The unit correlates well with a somewhat thicker deposit found at Ocean Drilling Program drilling sites in Saanich Inlet. 2001-A13 K.W. Conway et al. 1 CURRENT RESEARCH RECHERCHES EN COURS 2001 Article Article Titles Titres Purchase Information Information pour acheter 1 Royal British Columbia Museum, 625 Belleville Street, Victoria, British Columbia V8W 9W2