Paleohydrologic investigations in the vicinity of Yucca Mountain: Late Quaternary paleobotanical and polynological records

摘要

The primary objective of this research in the vicinity of the proposed Yucca Mountain Nuclear Waste Repository is the detection of episodes of increased runoff and groundwater discharge in this presently arid area. Ancient, inactive spring deposits in nearby valley bottoms, evidence for perennial water in presently dry canyons, and recent claims for extraordinary increases in precipitation during the last glacial age provide good reason to further investigate both lowland spring-discharge habitats, and upland drainages. The ultimate purpose is to assess the long-term variability of the hydrologic system in the vicinity of Yucca Mountain in response to naturally occurring climatic changes. This report presents the results of an initial assessment of the hydrologic stability of the candidate area based on a limited suite of middens from localities that, on geomorphic and hydrologic grounds, could have been close to ancient stream-side or spring environments. A secondary objective of this study is to compare the plant macrofossil data generated in this study to other records from the Candidate Area to determine if these new data are consistent with prior reconstructions. 66 refs., 4 figs., 13 tabs.