Sedimentary environments in the south-western Barents Sea during the last deglaciation and the Holocene: a case study outside the Ing?ydjupet trough

摘要

A lithological and foraminiferal study of newly acquired sediment cores outside the Ing?ydjupet (Ing?y Deep) trough has been carried out to improve constraints on the last deglacial history in the south-western Barents Sea. Three lithofacies and three foraminiferal facies were identified. The lowermost lithological unit is a diamicton interpreted as glacial till. It contains a low-abundance, ecologically mixed foraminiferal assemblage, presumably resulting from glacial reworking. Above the diamicton, a layer of ice-rafted debris (IRD), likely associated with intensive iceberg production, marks the initial destabilization of the marine-based ice sheet. At this time, ca. 15.6–15.0 Ky B.P., opportunistic foraminiferal species Nonionellina labradorica and Stainforthia spp. reached peak abundance. During the south-western Barents Sea ice-margin retreat, presumably corresponding to the B?lling interstadial, a sequence of glaciomarine laminations was deposited conformably on the layer of IRD. Sedimentation rates...