Terrigenous events and climate history of the Sophia Basin, Arctic Ocean

Abstract

Periods of enhanced terrigenous input to the ocean's basins of the North Atlantic have been reported for the last glacial period. We present a set of new sediment cores recovered from the Sophia Basin north of Svalbard which exhibit widespread ice-rafted debris layers reflecting enhanced terrigenous input throughout the last ∼200 ka B.P. Their consistent stratigraphic position, sedimentological character, high sedimentation rate, and geochemical characteristic point to synchronously deposited layers which we name terrigenous input events (TIEs). Owing to their higher densities, they generate excellent reflectors for sediment-penetrating acoustic devices and prominent acoustic layers in the imagery of sedimentary structures. Therefore TIEs can be used for regional acoustic stratigraphy. Each of the events can be linked to major glacial activity on Svalbard. However, the Early Weichselian glaciation is not recorded as a TIE and, in agreement with other work, might not have occurred on Svalbard as a major glacial advance to the shelf break. Nonsynchronous timing of western and northern sources on Svalbard points against sea level- induced iceberg discharge events. Copyright 2008 by the American Geophysical Union.