COLLABORATIVE RESEARCH: Plio-Pleistocene Mammal Faunas and Environmental Change in the Meade Basin of Southwestern Kansas: A Combined Stratigraphic, Faunal, and Isotopic Approach

合作研究：堪萨斯州西南部米德盆地的上更新世哺乳动物区系和环境变化：地层学、动物区系和同位素相结合的方法

• 批准号: 0207383
• 负责人: David Fox
• 金额: $ 4.5万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-15 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0207383&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; Plio; Pleistocene; Mammal

The primary purpose of this project is to determine the effects of abiotic and biotic factors on the community structure and morphology of small mammals, especially rodents, during the past 5.0 million years in the Meade Basin of southwestern Kansas. The Meade Basin is a unique natural laboratory, as more than 100 fossiliferous localities (representing at least 40 superposed intervals) spanning the entire later Cenozoic are found within a small area of approximately 45 km2. Three radiometrically dated ashes at 2.1, 1.2-1.5, and 0.67 Ma provide calibration points for part of the sequence, and a magnetostratigraphic chronology will be developed that will add considerable refinement to the basic stratigraphic framework. Further field mapping will hopefully solve a few remaining thorny stratigraphic problems, especially in the upper part of the Rexroad Formation. Systematic studies at appropriate museums will refine the rodent database. A preliminary stable isotope study of paleosol carbonate nodules and caliche beds in Pliocene sediments has revealed significant habitat and climatic gradient changes, reflecting the expansion of tropical grasses throughout the Great Plains during this time. The isotopic studies will be extended to additional localities and to mammalian tooth apatite, to better refine the record of environmental change and to examine the response of small mammal diets to environmental gradients. Finally, appropriate analytical methods will be used with the rodent database to examine the dynamics of community assembly and anatomical change within lineages. The Meade Basin rodent database and stable isotopic record will generate one of the most detailed historical records of habitat, climatic, and faunal change in a terrestrial animal community anywhere in the world, and the stratigraphic model resulting from this project will provide the primary source of late Cenozoic stratigraphic information for the Great Plains region of North America.

该项目的主要目的是确定过去 500 万年中堪萨斯州西南部米德盆地的非生物和生物因素对小型哺乳动物（尤其是啮齿动物）群落结构和形态的影响。米德盆地是一个独特的自然实验室，在大约 45 平方公里的小区域内发现了跨越整个新生代晚期的 100 多个化石产地（代表至少 40 个重叠区间）。三个 2.1、1.2-1.5 和 0.67 Ma 的辐射测年灰烬为部分序列提供了校准点，并且将开发磁性地层年代学，这将为基本地层框架增加相当大的完善。进一步的野外测绘有望解决一些剩余的棘手地层问题，特别是在 Rexroad 地层的上部。在适当的博物馆进行系统研究将完善啮齿动物数据库。对上新世沉积物中古土壤碳酸盐结核和钙质层的初步稳定同位素研究揭示了显着的栖息地和气候梯度变化，反映了这一时期热带草在整个大平原上的扩张。同位素研究将扩展到其他地区和哺乳动物牙齿磷灰石，以更好地完善环境变化的记录并检查小型哺乳动物饮食对环境梯度的反应。 最后，将使用适当的分析方法与啮齿动物数据库来检查群落组装的动态和谱系内的解剖变化。米德盆地啮齿动物数据库和稳定同位素记录将生成世界各地陆地动物群落栖息地、气候和动物区系变化的最详细历史记录之一，该项目产生的地层模型将提供北美大平原地区的晚新生代地层信息。