TWO MODES OF CLAY-MINERAL DISPERSAL PATHWAYS ON THE CONTINENTAL SHELVES OF THE EAST SIBERIAN SEA AND WESTERN CHUKCHI SEA

Abstract

The distribution of clay-mineral abundances on the inner continental shelves of the East Siberian and western Chukchi Seas well confirms to the dominant regional circulation pattern. The clay mineralogical analysis distinctly shows the two principal sources and dispersal pathways of these clay-mineral assemblages. The latitudinal (i.e., depth dependence) and longitudinal (i.e., source dependence) transition between clay-mineral assemblages explains that the illite-rich mineral assemblage derived largely from the Kolyma River is likely transported along the inner continental shelf by the eastward-flowing Siberian Coastal Current in the East Siberian Sea. Another assemblage of smectite- and kaolinite-rich sediments mostly derived ultimately from the Yukon River extends toward the Long Strait through the Bering Strait from the northern Bering Sea. In addition, sensitive variations in the clay-mineral assemblages reflect the association with water depth, which underscores the transportation and dispersal patterns to form the modern fine-grained sedimentary blankets.