A Collaborative Proposal: Late Quaternary Glacial and Paleoclimate Record in the Southern Uinta Mountains, Northeastern Utah

Uinta山脉保存完好，记录了最近更新世高山冰川的范围和行为。然而，这一记录还没有在大范围的尺度上得到详细的研究，最后一次冰川极大(LGM)和随后的冰川消融的时间也没有确定。记录Uinta山脉晚第四纪冰川的空间和时间范围是有必要的，原因有几个。首先，山脉的位置--位于年代久远的高山冰川地区的中心，毗邻博内维尔湖盆地的东部边缘--为研究博内维尔湖对犹他州东北部古气候和冰川的区域影响提供了巨大的潜力。其次，Uinta山脉的方位为研究在同一山脉内南北流动的大型冰川的记录提供了一个独特的机会。最后，冰雹的良好保存和不规则巨石的抗岩性为宇宙起源的表面暴露测年提供了理想的目标。我们建议使用常规和先进的研究方法相结合的方法来研究Uinta山脉的晚第四纪冰期和古气候记录，以追求以下目标：1)确定Uinta山脉在末次盛冰期期间和以来的冰川程度和时间。这项工作将包括：(1)对乌伊塔山南侧的地表地质进行详细的野外和航空摄影测绘；(2)对乌伊塔山西部、中部和东部末次盛冰期期间沉积的冰雹进行宇宙成因地表暴露年代测定；(3)从乌伊塔山南北坡由退缩冰川形成的湖泊中提取和研究湖泊沉积岩芯。由于冰川的范围是温度和降水的函数，冰川记录是气候变化的极好代表。我们将使用最新的更新世冰川的地貌记录来验证基于气候输入参数模拟冰川生长的数值模拟实验；这将允许对Uinta山脉的LGM古气候进行独特的确定。广泛影响本提案中概述的研究将产生超出追求核心科学目标的好处。首先，它将进一步加强阿什利国家森林(ANF)和威斯康星大学麦迪逊分校之间的持续关系。由于国家森林的公共使用和更密集的管理，ANF的管理者对林地的地质史产生了更大的兴趣，并在过去8年里支持了Uinta山脉的研究生研究(例如，DouGlass，2000；Munroe，2001；Carson，2003)，并继续支持当前的研究生研究(B.Laabs，这项研究；见支持函)。其次，博士生B.Laabs将参加新的NSF研究、教学和学习一体化中心(CIRTL)，这是一个由NSF赞助的项目，在威斯康星大学麦迪逊分校启动，旨在培养下一代大学理科教授。他将参加CIRTL课程和研讨会，重点是有效地使用研究方法在大学课堂上传播科学知识。Laabs将是首批获得证书的研究生之一，他们承认为在学术界的职业生涯做准备，并将NSF-UW-Madison合作伙伴关系的成果带入美国高等教育系统。最后，J.Munroe(米德尔伯里学院)以他在Uintas的研究生工作为基础，开始将本科生纳入他目前对该地区第四纪晚期历史的研究。这项拟议的研究为三个地质学专业的大四学生提供了在总体研究目标方面攻读本科论文的机会(有关更多信息，请参阅瑞安影响声明)。

ABSTRACTThe Uinta Mountains contain a well-preserved record of alpine glacier extents and behavior during the latestPleistocene. Yet, this record has not been studied in detail at the range-wide scale, and the timing of the Last GlacialMaximum (LGM) and subsequent deglaciation have not been determined. Documenting the spatial and temporal extent of late-Quaternary glaciation in the Uinta range is warranted for several reasons. First, the location of the range - central among well-dated alpine glacial localities and adjacent to the eastern edge of the Lake Bonneville basin - provides great potential for examining the regional effect of Lake Bonneville on paleoclimate and glaciation in northeastern Utah. Second, the orientation of the Uinta range provides a unique opportunity to study a record of large glaciers that flowed both north and south within a single mountain range. Finally, the excellent preservation of moraines and resistant lithology of erratic boulders provides ideal targets for cosmogenic surface-exposure dating. We propose to use a combination of conventional and advanced research methods to study the late-Quaternary glacial and paleoclimate record of the Uinta Mountains in pursuit of the following goals:1) Determine the extent and timing of glaciation in the Uinta Mountains during and since the LGM. Thiseffort will involve (1) detailed field and air photograph mapping of the surficial geology of the south flank ofthe Uinta Mountains (2) cosmogenic surface-exposure dating of moraines deposited during the LGM in thewestern, central, and eastern Uintas and (3) retrieval and study of lake sediment cores from lakes dammed by recessional moraines across the north and south slopes of the range.2) Reconstruct the latest Pleistocene paleoclimate from glacial records across the Uinta Mountains. Becausethe extents of glaciers are a function of temperature and precipitation, glacial records are excellent proxies of climate change. We will use the geomorphic records of latest Pleistocene glaciers to validate numericalmodeling experiments that simulate glacier growth based on climate input parameters; this will allow for aunique determination of LGM paleoclimate in the Uinta Mountains.Broader ImpactsThe research outlined in this proposal will yield benefits beyond pursuit of the core scientific objectives. First, it will further the ongoing relationship between the Ashley National Forest (ANF) and UW-Madison. Due to rising public use and more intensive management of National Forests, supervisors of the ANF have developed a greater interest in the geologic history of forest land and have supported graduate student research in the Uinta Mountains for the past 8 years (e.g., Douglass, 2000; Munroe, 2001; Carson, 2003) and continue to support current graduate research (B. Laabs, this study; see letter of support). Second, Ph.D. student B. Laabs will participate in the new NSF Center for the Integration of Research Teaching and Learning (CIRTL), an NSF-sponsored program that was launched at the UW-Madison to prepare the next generation of college science professors. He will participate in CIRTL courses and workshops focused on the effective use of research methods to disseminate scientific knowledge in the college classroom. Laabs will be among the first graduate students to receive a certificate acknowledging preparation for a career in academia and bring the fruits of this NSF-UW-Madison partnership into the U.S. higher education system. Finally, J. Munroe (Middlebury College) has built upon his graduate work in the Uintas and has begun including undergraduates in his current research on the late Quaternary history of the area. The proposed research provides the opportunity for three senior geology majors to pursue undergraduate theses on facets of theoverall research objectives (see RUI impact statement for more information).