Evidence from sedimentary structures for processes of sediment transport and deposition during post-Miocene time at Sites 645, 646, and 647, Baffin Bay and the Labrador Sea

Abstract

Nonbiogenic, primary physical sedimentary structures are, for the most part, restricted to Pliocene-Pleistocene strata at Leg 105 sites, after the onset of Northern Hemisphere glaciation. In Baffin Bay (Site 645), a predominantly ice-rafted record is punctuated by thin, graded and laminated, silt-mud couplets (turbidites) and ungraded, cross-laminated silts (possible bottom-current deposits). In the Pliocene record at this site, thick, sharp-based and ungraded sandy beds may have been emplaced by high-concentration sediment gravity flows. -from Authors