Research Objectives:
We will investigate paleoenvironmental conditions during the late Paleozoic and Mesozoic in central interior Antarctica. The 4-kilometer-thick sequence of sedimentary rocks in the Beardmore Glacier area, known as the Beacon Supergroup, records 90 million years of Permian through Jurassic history of this high-paleolatitude sector of Gondwanaland. The sequence accumulated in a foreland basin with a rate of subsidence approximately equal to the rate of deposition. The deposits have yielded diverse vertebrate fossils, fossil forests, and exceptionally well preserved plant fossils that give a unique glimpse of glacial, lake, and stream/river environments and ecosystems and provide an unparalleled record of the depositional, paleoclimatic, and tectonic history of the area.
We plan to integrate sedimentologic, paleontologic, and ichnologic observations to answer the following focused questions:
+ What are the stratigraphic architecture and alluvial facies of Upper Permian to Jurassic rocks in the Beardmore Glacier area?
+ In what tectonostratigraphic setting were these rocks deposited?
+ Did vertebrates inhabit the cold, near-polar Permian floodplains, as indicated by vertebrate burrows, and can these burrows be used to identify for the first time the presence of small early mammals in Mesozoic deposits?
+ How did bottom-dwelling animals in lakes and streams use substrate ecospace, how did ecospace use at these high paleolatitudes differ from use in equivalent environments at low paleolatitudes, and what does burrow distribution reveal about the seasonality of river flow and thus about paleoclimate?
Answers to these questions will
+ Clarify the paleoclimatic, basinal, and tectonic history of this part of Gondwanaland;
+ Elucidate the colonization of near-polar ecosystems by vertebrates;
+ Provide new information on the environmental and paleolatitudinal distributions of early mammals; and
+ Allow semiquantitative assessment of the activity and abundance of bottom-dwelling animals in different freshwater environments at high and low latitudes.
We expect this project to contribute significantly to an understanding of paleobiology and paleoecology on a high-latitude floodplain during a time in Earth’s history when the climate was much different than it is today.
