Collaborative Research on Surface-Exposure Dating of Quaternary Glacial Sequence for the White Mountains, CA-NV

几乎没有长期的冰川记录，而且这些记录在地理上是分散的。怀特山脉位于加利福尼亚州和内华达州中部内华达山脉中部以东，拥有北美最完整的冰川事件沉积序列之一。新的地表暴露测年方法在使用前后的新应用使得有可能通过分析积累在地表巨石中的多种宇宙成因同位素来确定地貌表面的年龄。这个合作项目的目标是利用这些表面暴露测年方法，结合相关的火山岩、岩石清漆、土壤和风化作用的日期，开发白色山脉的数字冰川年代学。研究人员将在内华达山脉使用同样的方法，以便准确地比较这两项记录，并区分天气气候学和构造历史作为控制山脉冰川的影响。这项研究有望提供北美最完整的冰川事件大陆记录之一。所获得的结果还将为将大陆冰川记录与其他大陆和环境变化的长期记录以及与公认的海洋记录进行比较提供年表。这项研究将使用多种不同的测年技术，其中一些还处于发展的初级阶段，以帮助解开怀特山的冰川年代学。这项跨学科的研究工作将有助于评估新的测年方法以及物理地理学家和其他地球科学家使用的各种传统冰川、土壤和地貌技术的可行性。这项研究将有助于我们理解怀特山保存完好的冰川序列与气候、构造活动和植被变化的关系。这项研究将把白山冰川序列与其他区域大陆地貌调查和漫长的冰川-海洋记录相关联，并将提供对美国西部水文平衡重大变化的规模和时间的洞察。

Few long-term glacial records exist, and the ones that do are geographically scattered. The White Mountains, immediately east of the central Sierra Nevada in California and Nevada have one of the most complete sequences of deposits from glacial events in North America. New pre- and post-applications of new surface exposure dating methods make it possible to determine ages of geomorphic surfaces through analyses of multiple cosmogenic isotopes that accumulate in surface boulders. The goal of this collaborative project is to develop a numerical glacial chronology for the White Mountains using these surface-exposure dating methods in conjunction with dates based on associated volcanics, rock varnish, soils, and weathering. The investigators will use the same approach in the Sierra Nevada in order to an accurately compare the two records and to discriminate the effects of synoptic climatology versus tectonic history as controls on the glaciation of the mountain ranges. The research is anticipated to provide one of the most complete continental records of glacial events in North America. The results obtained also will provide a chronology for comparing a continental glacial record with other long-term records of continental and environmental change and with the well-established marine record. The study will use multiple and varied dating techniques, some of which are in the intial stages of development, to help unravel the glacial chronology of the White Mountains. This interdisciplinary research effort will help assess the viability of new dating approaches and various traditional glacial, soils, and geomorphological techniques used by physical geographers and other earth scientists. The research will contribute to our understanding of how the well-preserved glacial sequence in the White Mountains relates to changes in climate, tectonic activity, and vegetation. The study will correlate the White Mountain glacial sequence to other regional continental geomorphic investigations and to the lengthy glacio-marine record, and it will provide insight into the scale and timing of large changes in the hydrologic balance of the Western United States.