MARINCOVICH, LOUIE, JR., U.S. Geological Survey, Menlo Park, CA

ABSTRACT: Paleogeographic Implications of Coeval "Mesozoic" and Paleocene Mollusks, Arctic Alaska

A molluscan fauna from the Prince Creek Formation, northern Alaska, is the first evidence for an indigenous Paleocene shallow-water biota within a discrete Arctic Ocean Basin faunal province. The Alaskan fauna is assigned a Danian age because several taxa also occur in Danian molluscan faunas of the North American Western Interior, the Canadian Arctic Islands, and northwestern Europe that are well dated with planktonic microfossils. This Danian fauna also contains a number of relict "Mesozoic" genera. The presence of these genera in situ with Danian mollusks implies a unique paleogeographic setting. A high percentage of endemic species, and two endemic genera, emphasize the degree to which the Arctic Ocean was geographically isolated from the world ocean during the earliest Tertiary. he presence of several well-known "Mesozoic" taxa in this Danian fauna also implies that terminal-Cretaceous extinction processes were less effective in high northern latitudes than elsewhere.

AAPG Search and Discovery Article #90992©1993 AAPG Pacific Section Meeting, Long Beach, California, May 5-7, 1993.