Global Change: Genesis & Paleoenvironmental Record of Dunes on the Southern High Plains

这项研究是对古气候的调查， 沙丘地意义和晚第四纪历史， 在南部高平原上的新月形沙丘（沙丘边缘的干盐湖盆地）。 三个主要假设将被测试：1）沙丘 南部高平原上的农田是在 9000年和4500年B. P.，从1000年前开始，历史上; 2） 南部高平原的新月形区域同时形成， 在第四纪晚期， 干旱期相邻干盐湖沉积物; 3）全新世 沙丘和弦月的形成 是区域性干旱的结果。 有 研究的几个重要方面。 沙丘的记录 建设和沙丘运动应该提供一个长期的（晚 第四纪）干旱和风蚀的高平原记录 面 研究沙丘活动的历史记录沿着 历史气候数据将开始提供一些估计， 荒漠化之前必须跨越的气候阈值 从该地区开始。 研究弦月也很重要 因为它们是埃斯塔卡多河畔拉诺唯一的沉积地点 有可能成为一个可确定年代的古环境 和过去3万年的地层记录。 的 建议对南部高平原进行研究， 北方高原沙丘研究（由NSF，USGS， 和美国宇航局），并将有助于亚大陆规模的看法， 晚第四纪风成侵蚀和沉积作用及其伴随物 气候影响。

The proposed research is an investigation of the paleoclimatic significance and late-Quaternary history of sand dune fields and lunettes (dunes fringing playa basins) on the Southern High Plains. Three principal hypotheses will be tested: 1) the sand dune fields on the Southern High Plains formed synchronously between 9000 and 4500 yrs B.P., since 1000 yrs B.P., and historically; 2) the lunettes of the Southern High Plains formed synchronously and episodically during the late Quaternary and were derived from sediments in adjacent playas during droughts; 3) Holocene construction of the sand dunes and the lunettes occurred synchronously and was the result of regional drought. There are several significant aspects of the research. The record of dune construction and dune movement should provide a long-term (late Quaternary) record of drought and wind erosion of the High Plains surface. Studying the historic record of dune activity along with historic climate data will begin to provide some estimates of the climatic thresholds that must be crossed before desertification begins in the region. Studying the lunettes is also important because they are the only sites of deposition on the Llano Estacado with a demonstrated potential for a dateable paleoenvironmental and stratigraphic record spanning the past 30,000+ years. The proposed research on the Southern High Plains complements current dune studies on the Northern High Plains (sponsored by NSF, USGS, and NASA) and will contribute to a subcontinental-scale view of late-Quaternary eolian erosion and sedimentation and attendant climatic implications.