Studies on Little Diomede Island

Little Diomede Island (66° 45'N, 168° 54' W) is a granitic pluton with wave-cut cliffs supporting a relatively flat upland surface. The age and origin of the 363 m upland is unknown and hence is the basis for this research. Although no geological reports of the island has appeared in the literature, the politically, oceanographically and geologically strategic position of Little Diomede Island undoubtedly holds clues concerning aspects of the Late Pliocene and Early Pleistocene glacial and sea level history of central Beringia. This region of the Arctic has been the focus of interdisciplinary Quaternary research, yet critical paleoenvironmental questions remain unanswered. Workers on the western coast of Alaska and the eastern coast of Chukotka (Russia) are challenged by differences regarding sea level and glacial histories on either side of the Bering Strait. However, few researchers have actually worked on the islands in the Bering Strait. These islands are remnants of the emergent ice-age landscape and can bridge the paleoenvironmental gap between eastern and western Beringia. This information will also be helpful in determining the neotectonic, glacial and sea level history of the narrowest part of central Beringia.

The problem to be addressed is the investigation of the age and origin of the upland surface on Little Diomede Island. Two hypotheses will be tested:

1. The surface is marine in origin and can be correlated with the well-documented sea level events in western and northern Alaska. If the surface is marine, it is likely that it was formed during the Pliocene.
2. The surface is glacial in origin. If it is glacial in origin, questions regarding age, ice extent and primary ice flow direction will be addressed.

I collected rock samples for cosmogenic isotope analysis as well as investigated the island for all possible clues as to either a glacial or marine origin.