Marmara and Black seas: piston coring and high-resolution seismic surveying

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Twenty sea days are requested for work in the SW Black Sea and NE Marmara Sea, forpiston and gravity coring and seismic profiling. The SW Black Sea was thoroughly mapped in two NSERC-funded cruises in 2005 and 2008 using a Kongsberg EM3000-series multibeam system, a Huntec deep-tow boomer profiler and an acoustic Doppler current profiler. In 2010 current velocities associated with a strong channelized saline underflow in this area were measured using an aDcp deployed on the British AUV AutoSub-III, and a set of bottom grab samples and conductivity-temperature-depth (CTD) profiles were obtained to characterize surface sediments and physical properties of the saline underflow. The proposed coring is an essential follow-up to this earlier work in order to ground-truth ages and facies of the sedimentary strata imaged in the geophysical data sets, and sedimentary processes associated with the modern saline underflow. Without dated sedimentary records from core samples, the seismic and multibeam records have limited value, and interpretations of the genesis of these deposits and the paleoceanography related to Holocene reconnection of the Black Sea to the world ocean remain speculative. The NE Marmara Sea was surveyed and sampled in 1998, 2000, 2002, 2005 and 2008 using a Huntec deep-tow sparker profiler, short corer. Long piston cores are needed to establish the ages of key surfaces and deposits. Key questions remain unanswered and/or published interpretations which have been challenged by other workers need additional support.