2. Attempt to establish the frequency of earthquakes (particularly very large events; which are greater than magnitude 8 in this region of the Cascadia convergent margin);
3. Advance the understanding of diagenesis in organic-rich sedimentary basins and especially of the role of microbial processes. The predominantly finely laminated (varved) sediments that are believed to have accumulated in the inlet since deglaciation will be cored at two sites in the deeper axial region of the fjord; these two sites (at 200 and 225 m water depth) have significantly different organic contents and accumulation rates. Saanich Inlet will provide an important companion to the high-resolution Site 893 drilled in Santa Barbara Basin.
Approximately 100 to 125 m of Holocene diatomaceous silts and clays and upper Pleistocene glaciomarine muds will be cored with the advanced hydraulic piston corer (APC) to refusal at the two sites. Both sites will be triple APC cored. Only the A hole from each site will be measured using the multi sensor track (MST), split, and photographed on board. The B and C holes will be measured using the MST during Leg 169 and returned to the Gulf Coast Repositiory for further work. Temperature measurements will be made in the lowermost part of Site SI-02B if time permits.
To 169S Introduction
169S Table of Contents