Bering Strait gateway currents and their implications for sediment distribution, shelf conceptual models and economic potential

This paper addresses a gap in our knowledge about strong geostrophic current control of epicontinental shelf deposits. The northward current that accelerates towards the Bering Strait gateway affects sediment distribution in the northern Bering Sea leading to the Strait, in the Strait and in the Chukchi Sea where currents slack. Leeside sand bodies develop when the northward geostrophic current shears and accelerates against topographic projections into the current. When currents slack downstream, leeside sand bodies deposit. Yearly 1 m and decadal catastrophic up to 5 m storm surges resuspend the Yukon sediment. Most of this sediment is then entrained by strong northward currents and transported up to 1000 km north, bypassing Chirikov Basin and the Bering Strait gateway, to deposit in the Chukchi Sea. Northern Bering Sea depositional patterns reinforce evidence that epicontinental shelf sedimentary sequences are different from more regular proximal to distal offshore sequences on marginal shelves. Compared with marginal shelves, strong currents, Coriolis force and topographic constrictions result in sediment bodies detached from the shoreline and large areas of sediment bypass on epicontinental shelves. The Bering Sea currents prevent Holocene sediment from covering both relict gravel with the world's largest offshore gold deposits and large areas of surficial sediment with heavy-mineral concentrations >16% that contain scarce rare earth metals.