9405247 CURREY In order to better understand the possible direction and consequences of future climate changes, geographers and other earth scientists must first identify and understand the dynamics of climatic changes that have occurred in the past. Paleoclimatic changes can be analyzed through examination of the responses of geomorphic systems, records of which are preserved in stratigraphic records and other characteristics of different landforms. This doctoral dissertation research project will examine environmental change during the late Quaternary Period in the Salt Basin of western Texas. Deposits from a number of different sites in and near playa basins that once were lakebeds will be gathered and analyzed using a variety of dating procedures. Stratigraphic sections beneath the floor of the playa will be examined to identify materials contained within lake sediments, thereby providing evidence of short-term climatic shifts. Peripheral sections beside the playas contain evidence of aeolian activity in gypsum dune deposits. Other features along the playa margin, such as spits and beach ridges, permit interpretation of deep-water lacustrine processes. Further away from the playas, landforms produced by wind and running water record variability of formative environments. Among the research techniques that will be used to analyze materials derived from sample sites are thermoluminescence and optically simulated luminescence (TL/OSL) dating, radiocarbon dating, and stable isotope rate analysis. This research will provide valuable new insights about the chronology of climate and landscape change in the southern Great Plains. In doing so, it will further the comprehensive picture of environmental change in North America in the wake of the last major glaciation, thereby advancing understandings of Earth system history, a major facet of the U.S. Global Change Research Program. As a doctoral dissertation improvement award, this award also will pr ovide support to enable a promising student to establish a strong independent research career.
