Provenance and dispersal of terrigenous sediments in the Bering Sea slope: Implications for late glacial land-ocean linkages

Clay mineralogy and grain-size properties from two well-dated, high resolution sediment cores recovered from the western Alaskan continental are used to decipher millennial-scale changes in sediment provenance and sedimentary transport during the last 32 kyrs. During the last glacial maximum, the depositional environment was characterized by hemipelagic background sedimentation with overregional sediment sources. Maximum values of fluvial suspensions and kaolinite concentration occur during the late Heinrich event 1 (H1), which point to the sudden influx of clay-laden meltwaters from Northern Alaska. For the subsequent deglacial Bølling-Allerød (BA) interval, meltwater supply changed from glacial-fluvial to more fluvial, caused by warming that probably led to increased snow melt and permafrost thaw. The fresh-water lid might have eased local overturning ventilation in the Bering Sea water that promoted the deposition of laminated sediments. During Holocene sea-level rise the shore line moved far away from the site and reduced terrigenous sediment influx. Strong contour currents possibly led to the winnowing of sediments and caused residual sand enrichment