Hydrologic, Geomorphic, & Chronologic Record of Paleofloods,Lake-Building Events & Climate Change During the Late Quat- ernary: Analysis of Integrated Fluvial/Pluvial Lake

9316443井气候变化和水文响应记录了许多沉积和地貌特征，包括湖相层序和河流地貌。死谷的曼利湖是第四纪河流排泄的终点。径流的供应来自三个主要来源：内华达山脉东坡因冰川融化而排水的欧文斯河系统，因横跨山脉地形抬升而产生的降水而排干圣贝纳迪诺山脉的莫哈维河，以及发源于较低的黑山和森林山的阿马托萨河。目前，阿马托萨河是唯一一条流入死亡谷的河流。该项目将探讨1)阿马戈萨河是如何从气候条件变化或地下水中获得地表流量的，以及2)阿马戈萨河流量在第四纪晚期死亡谷造湖事件中所起的相对作用。了解阿玛戈萨河水系的地貌和水文演变很重要，原因如下：(1)它在第四纪晚期死亡谷潜在流域总面积中贡献了15,540平方公里(Hunt等人，1966)(2)阿玛戈萨河地表径流来自低海拔水系，可作为不受冰川作用或高海拔地形降水影响的晚第四纪气候制度的古气候指标。(3)阿玛戈萨河流域位于气候/地貌带的外围，有可能指示河流/湖泊沉积中保存的大范围气候波动。(4)它排干了美国在内华达州尤卡山拟建的高放射性废物储存库的潜在地点。我们建议：(A)重建阿马戈萨河晚第四纪洪泛史；(B)确定浮游的现代水文和气候条件；(C)重建死谷晚第四纪造湖事件；(D)主要流域晚第四纪洪泛史及其与古气候动态的关系。***

9316443 Wells Climate variations and hydrologic responses are recorded in numerous sedimentologic and geomorphic features, including lacustrine sequences and fluvial landforms. Pleistocene Lake Manly in Death Valley was the end point for river discharges during the Quaternary. The supply of runoff was from three major sources: The Owens River system draining the eastern slopes of the Sierra Nevada in response to glacial meltwaters, the Mojave River draining the San Bernardino Mountains in response to precipitation due to orographic uplift over the Transverse Ranges, and the Amargosa River which heads in the lower Black and Timber Mountains. Presently, the Amargosa is the only river to flow into Death Valley. This project will address 1) how the Amargosa River acquired its surface flow, from anamolous climatic conditions, or from groundwater, and 2) the relative role the Amargosa River discharge has in contributing to lake-building events in Death Valley during the late Quaternary. Understanding the geomorphic and hydrologic evolution of the Amargosa River system is important for the following reasons; (1) It contributions a significant 15,540 Km2 to the total potential drainage area of Death Valley in the late Quarternary (Hunt et al., 1966) (2) Amargosa River surface runoff comes from a low-elevation drainage system that may serve as a paleoclimatic indicator of late Quaternary climatic regimes unaffected by glaciation or high elevation orographic precipitation. (3) The drainage basin of the Amargosa River lies on the periphery of climatic/physiographic zones where it has the potential to indicate large-scale climatic fluctuations preserved in fluvial/lacustrine sediments. (4) it drains the potential site of the nations's proposed high-level radioactive waste repository at Yucca Mountain, Nevada. We propose to (a) reconstruct the late quaternary flood history of the Amargosa River (b) determine the modern hydrologic and climatic conditions for floo ding (c) reconstruct late Quaternary lake-building events in Death Valley and (d) the late Quaternary flood histories of the major drainages and their relationship to paleoclimate dynamics. ***