气候变化领域集成服务门户(CCPortal): Paleohydrology of southwest Nevada (USA) based on groundwater 234U/238U over the past 475 k.y.

CCPortal

DOI	10.1130/B35168.1
	Paleohydrology of southwest Nevada (USA) based on groundwater 234U/238U over the past 475 k.y.
	Wendt K.A.; Pythoud M.; Moseley G.E.; Dublyansky Y.V.; Edwards R.L.; Spötl C.
发表日期	2020
ISSN	167606
起始页码	793
结束页码	802
卷号	132 期号:2021-03-04
英文摘要	Subaqueous calcite deposited on the walls of Devils Hole 2 cave (Nevada, USA) represents a unique archive for geochemical variations within the regional aquifer. Here, we present a 475,000-year record of initial 234U/238U activity ratios in delta notation (δ234U0). Results show a range in values from 1851-1616‰. Variations in δ234U0 coincide with interglacial-glacial cycles over the past 475,000 years. Maximum δ234U0 values correspond to the last five glacial intervals, during which southwest Nevada experienced cool, pluvial conditions. Minimum δ234U0 values correspond to interglacial intervals, during which this region experienced warm, arid conditions. We propose that an elevated water table during glacial periods inundated previously dry bedrock and basin sediments, thereby leaching excess 234U accumulated in these materials. We interpret Devils Hole 2 cave δ234U0 as a proxy for water-rock interactions in this regional aquifer, which is ultimately tied to the surface moisture conditions at recharge zones. The mechanism proposed here serves as a testable hypothesis and possible analogue for future subaqueous speleothem studies in similar hydrogeologic settings. Due to its unprecedented duration, the Devils Hole 2 cave δ234U0 record provides the first paleo-moisture record in southwest Nevada for marine isotope stages 10-12. In addition, high-precision δ234U measurements of modern groundwaters sampled from Devils Hole 2 cave are presented. © 2019 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184803
作者单位	Institute of Geology, University of Innsbruck, Innrain 52, Innsbruck, 6020, Austria; Department of Earth Sciences, University of Minnesota, 116 Church St. SE, Minneapolis, MN 55455, United States
推荐引用方式 GB/T 7714	Wendt K.A.,Pythoud M.,Moseley G.E.,et al. Paleohydrology of southwest Nevada (USA) based on groundwater 234U/238U over the past 475 k.y.[J],2020,132(2021-03-04).
APA	Wendt K.A.,Pythoud M.,Moseley G.E.,Dublyansky Y.V.,Edwards R.L.,&Spötl C..(2020).Paleohydrology of southwest Nevada (USA) based on groundwater 234U/238U over the past 475 k.y..Bulletin of the Geological Society of America,132(2021-03-04).
MLA	Wendt K.A.,et al."Paleohydrology of southwest Nevada (USA) based on groundwater 234U/238U over the past 475 k.y.".Bulletin of the Geological Society of America 132.2021-03-04(2020).