Claim: The beaches of Cape Espenberg see additions such as bones of Pleistocene megafauna, modern and ancient shell valves, and driftwood (concentrating more in the storm beach).
Evidence: Although in the long-term, as established by geological 14C ages, over the last 4000 years, sand transport is onshore and progradational, in the short term, storms and transient current reversals lead to offshore transport and erosion of Espenberg beaches. Locally, beaches have witnessed significant width and depth reductions in the last five years; current reversals are also possibly more common. Over 4,000 years of prehistory are revealed at Cape Espenberg, as documented by archaeological surveys since the 1950s when J.Louis Giddings visited the Cape. A secondary source of sand may be as a fluvial addition from south-trending paleo-Noatak and Kobuk rivers cross the exposed subcontinent of Beringia, and reworked into Pleistocene dunes during lower sea levels. A variety of clastic additions are common on the beach; these include the bones of Pleistocene megafauna (mostly horse, bison or mammoth), modern and ancient shell valves. Drift wood is concentrated in the storm beach and within the mouths of surge channels that cross cut the beach ridges.