Revised Tertiary Stratigraphy and Paleontology of the Western Beaver Divide, Fremont County, Wyoming

Emry, Robert J. Revised Tertiary Stratigraphy and Paleontology of the Western Beaver Divide, Fremont County, Wyoming. Smithsonian Contributions to Paleobiology, number 25, 20 pages, 6 figures, 1975.•In the western Beaver Divide area in west-central Wyoming, a lens of coarse Tertiary volcanic conglomerate and tuff disconfqrmably overlies Uintan rocks of the Wagon Bed Formation. The coarse volcaniclastic rocks were previously regarded as a faciès of the Beaver Divide Conglomerate Member of the Chadronian White River Formation, although fossil mammals from the volcaniclastic unit are species known otherwise only from Uintan rocks. Reexamination of field relations has shown that the White River Formation disconformably overlies the volcaniclastic unit. The "lower Uinta C" temporal equivalence indicated by the fossils from the volcaniclastic unit is no longer anomalous; the underlying Wagon Bed Formation has fossil mammals indicating "Uinta B" equivalence, and the overlying White River Formation has a fairly diverse Chadronian fauna. The Uintan volcaniclastic unit is assigned to the Wiggins Formation. The Beaver Divide Conglomerate Member is restricted to conglomerate in the lower part of the White River Formation. It is composed predominantly of clasts of locally derived Precambrian crystalline rocks. OFFICIAL PUBLICATION DATE is handstamped in a limited number of initial copies and is recorded in the Institutions annual report, Smithsonian Year. SI PRESS NUMBER 6013. SERIES COVER DESICN: The trilobite Phacops rana Green. Library of Congress Cataloging in Publication Data Emry, Robert J. Revised tertiary stratigraphy and paleontology of the Western Beaver Divide, Fremont County, Wyoming. (Smithsonian contributions to paleobiology, no. 25) 1. Geology, Stragraphic•Tertiary. 2. Paleontology•Wyoming•Fremont Co. 3. Paleontology• Tertiary. I. Title: Revised tertiary stratigraphy and paleontology of the Western Beaver Divide ... II. Series: Smithsonian Institution. Smithsonian contributions to paleobiology, no. 25. QE701.S56 no. 25 [QE691] 560'.8s [551.7'8'0978763] 75-8799