Contribution of detrital materials from the Yukon River to the continental shelf sediments of the Bering Sea based on the electron spin resonance signal intensity and crystallinity of quartz

Abstract

Bering Sea sediments contain detrital materials from the Yukon River. These materials may contain records of past climate changes in the Arctic area, such as the melting of glaciers around the drainage basin of the Yukon River, which help to understand hydrological cycle in this area. In the Bering Sea, however, the spatial extent and pattern of the detrital materials supplied from the Yukon River is not yet fully understood. Here we developed a method to identify clay- to sand-sized detrital materials derived from the Yukon River based on electron spin resonance (ESR) intensity of the E1' center and the crystallinity of quartz. We then estimated the spatial pattern of quartz contributed by the Yukon River on the Bering Sea shelf by applying the method to core-top samples from the continental shelf and slope of the eastern Bering Sea. The results showed a large contribution of sand-sized quartz from the Yukon River to wide areas of the continental shelf and slope, whereas contributions of clay- to silt-sized quartz from the Yukon River were small, except on the northeastern shelf. These spatial distribution patterns suggest that sand-sized quartz was repeatedly reworked and transported by processes such as storm surges to the outer continental shelf, whereas the clay- to silt-sized quartz on the northeastern shelf was supplied, as suspended materials, directly from the Yukon River.