PROBABLE COOL WATER ORIGINS OF A PERMIAN CARBONATE UNIT IN THE ALEXANDER TERRANE, ALASKA

In the Alexander terrane in the Prince of Wales region of Alaska, an overlooked Permian carbonate unit crops out on the eastern shore of Suemez Island. The first mention of the unit appears in the United States Geological Survey from the 1920’s, but the unit was only mentioned -- not described, measured, or mapped. Fieldwork conducted in the summer of 2015 involved measuring and collecting fossil/lithological samples of the Permian section. The section is in the process of being described and the taxa are being identified and cataloged. Preliminary results indicate the Permian unit is a slightly-folded, blue to gray limestone with cool or cold water origins that has undergone pervasive silicification. Macro-fossils are sparse but include bryazoans and brachiopods. The bedding in the unit may indicate seasonal storm events where brachiopods are concentrated in beds with a chaotic orientation and a possible mixing zone of both siliceous and carbonate materials from the shelf slope. Utilizing the fossils and sedimentary structures, correlation of the overlooked unit to other Permian units in the Alexander terrane is possible. The project will provide potential information about depositional environments, the paleoecology, and the paleoclimate of the Permian unit. If correlated to other Permian units, the project could also provide an insight to oil/natural gas producing Permian units within the Alexander terrane.