PALEONTOLOGICAL RECONNAISSANCE OF THE FREDERIKA FORMATION, WRANGELL-ST. ELIAS NATIONAL PARK AND PRESERVE, SOUTHEASTERN ALASKA

The Frederika Formation is a largely unstudied complex of up to 600 meters of depositionally variable terrestrial volcaniclastic sediments that appear to have been deposited over several million years during the early to mid-Miocene in what is now Wrangell-St. Elias National Park and Preserve in southeastern Alaska (62°N, 144°W). These strata contain an intriguing mix of depositional sequences capable of yielding new information from a climatically variable period of Earth history, particularly in regards to understanding the nature of “pulses” of environmental change (such as the mid-Miocene climatic optimum ~ 15 Ma). Paleontological resources within the Frederika Formation are abundant. In addition to a wide variety of very well-preserved paleobotanical specimens (including Betula, Acer, Alnus, Metasequoia and a variety of other conifers), the diversity of lithotypes in which the material was preserved is indicative of broadly variable depositional environments (including paleosol sequences, thick coal beds, lacustrine deposits, silty tuffaceous sandstones and other tephra-rich materials). Within these varied lithotypes, the potential for new discoveries of vertebrate fossils and fossil palynomorphs is outstanding, as is the potential for obtaining radiometric dates from tuffaceous deposits within these strata. Reconnaissance work in 2001 included the aerial examination and photographic imagery of 200+ miles of pedolithic volcanic claystones and siltstones. Accessible outcrop exposures both in, and lateral to, the Frederika Formation type area were recorded with a GPS and transferred to GIS maps. Fieldwork in the summer of 2003 involved on-the-ground vertebrate fossil prospecting and paleobotanical collecting efforts of known fossil sites and the identification of new potential sites. Results from these preliminary paleontological investigations provide a basis from which comprehensive research and resource protection plans are now being developed.