177 Scientific Prospectus

SAMPLING STRATEGY

During Leg 177, the upper sections (approximately 200 m) at each site will be recovered by APC in three holes (except for Site TSO-2B). The archive halves (permanent and temporary) in all holes will not be sampled aboard ship, and the permanent archive will be designated post-cruise. Sampling for high-resolution isotopic, sedimentologic, and micropaleontologic studies will be conducted after construction of the spliced composite section. Most of the high-resolution sampling will be deferred until after the cruise; however, the upper few cores in each hole that contain high porosity sediments that may be disturbed during transport to the Bremen repository will be sampled on board ship. High-resolution sampling is anticipated for most of the upper APC and XCB cores (5-cm intervals), with 10 to 20 cm³ needed for each sample, depending on the abundance of microfossils (especially benthic foraminifers). Whenever possible, whole round samples for pore-water geochemical analyses will be taken from intervals in holes that are not critical for constructing the composite section. U-channel sampling for paleomagnetic and rock magnetic studies will be conducted in the archive half along the composite sampling splice where appropriate. There is a possibility that diatom mats will be encountered in some sites south of the Polar Front. These mats will be sampled by taking a continuous slab of sediment from the working half. The sampling plan for Leg 177 must be approved by the sampling allocation committee (SAC), consisting of the Co-chiefs, Staff Scientist, and Curatorial representative. The initial sampling plan is preliminary and can be modified depending upon actual material recovered and collaborations that may evolve between scientists during the leg.