Ocean Drilling Program Leg 169S: surficial geology, stratigraphy and geomorphology of the Saanich Inlet area, southeastern Vancouver Island, British Columbia
2001; Elsevier BV; Volume: 174; Issue: 1-4 Linguagem: Inglês
10.1016/s0025-3227(00)00140-7
ISSN1872-6151
AutoresDavid Huntley, Peter Bobrowsky, John J. Clague,
Tópico(s)Climate change and permafrost
ResumoThis paper provides: (i) a descriptive overview of the late Pleistocene and Holocene geology and geomorphology of the region surrounding Saanich Inlet; and (ii) the palaeogeographic setting for discussion of the oceanographic record at ODP leg 169S sites 1033 and 1034. The dominant deposits and landforms in the Saanich Inlet area are similar to those of late Pleistocene marine-influenced glacial environments and modern fjord inlets dominated by retreating tide-water glaciers. Patterns of ice retreat, meltwater drainage and sea-level change are reconstructed for the interval 4000–15 000 calendar years before present (yrBP). The flux of meltwater and sediment into Saanich Inlet was greatest between ca. 12 000 and 15 000 yrBP. At that time, sea level was up to 90 m higher relative to land than today. During deglaciation, tidewater glaciers occupying Chemainus, Cowichan and Koksilah valleys entered a marine embayment that formed in the vicinity of Cowichan Bay, Satellite Channel, Saanich Inlet and Saanich Peninsula. In the early Holocene, relative sea level fell to a low stand perhaps tens of metres below the present datum, and the surface area of Saanich Inlet and Satellite Channel was much reduced. By the middle Holocene, sea level had risen to near its present position, and modern drainage patterns and oceanographic conditions were established.
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