Doctoral Dissertation Research: Reconstruction of Late Quaternary Climate Patterns from Lacustrine, Aeolean, and Alluvial Deposits of the Salt Basin in West Texas

[405247] CURREY为了更好地了解未来气候变化的可能方向和后果，地理学家和其他地球科学家必须首先确定和了解过去发生的气候变化的动态。古气候变化可以通过考察地层学记录和其他不同地貌特征中保存下来的地貌系统的响应来分析。本博士论文研究项目将研究德克萨斯州西部盐盆地晚第四纪的环境变化。从曾经是湖床的playa盆地内和附近的许多不同地点收集沉积物，并使用各种测年程序进行分析。将对湖底下的地层剖面进行检查，以确定湖泊沉积物中包含的物质，从而提供短期气候变化的证据。playas旁边的外围剖面包含石膏沙丘沉积物中风成活动的证据。盐湖边缘的其他特征，如喷口和海滩山脊，可以解释深水湖泊的作用。远离playas的地方，风和流水形成的地貌记录了形成环境的可变性。将用于分析来自样品地点的材料的研究技术包括热释光和光学模拟发光（TL/OSL）定年、放射性碳定年和稳定同位素率分析。这项研究将为大平原南部气候和景观变化的年代学提供有价值的新见解。在此过程中，它将进一步全面了解最后一次大冰期后北美环境变化的情况，从而促进对地球系统历史的理解，这是美国全球变化研究计划的一个主要方面。作为博士论文改进奖，该奖项还将为有前途的学生建立强大的独立研究生涯提供支持。

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.