Paleoecology of an Arctic Estuary

An alternating sequence of black silt and clay units, coarse sand and gravel units, occurs to depths of 30 ft below sea level in sediments underlying the Esatkuat Lagoon, directly northeast of the village of Barrow, Alaska. These beds represent one of the changing strandline environments which produced the Gubik formation (Pleistocene) of northern Alaska. A radiocarbon date at the base of the sequence indicates that these conditions first occurred 6450 yr BP. The silt-clay units were deposited under anaerobic conditions while a gravel bar separated the estuary from the ocean. The sand-gravel units resulted from destruction and spreading of the gravel bar inland under marine conditions.