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

摘要 尤因塔山脉保存了保存完好的更新世末期高山冰川范围和行为的记录。然而，这一记录尚未在大范围范围内进行详细研究，末次盛冰期（LGM）和随后的冰消期的时间尚未确定。出于多种原因，有必要记录尤因塔山脉晚第四纪冰川作用的空间和时间范围。首先，该山脉的位置位于历史悠久的高山冰川地区的中心，毗邻博纳维尔湖盆地的东部边缘，为研究博纳维尔湖对犹他州东北部古气候和冰川作用的区域影响提供了巨大的潜力。其次，尤因塔山脉的方向为研究单一山脉内向北和向南流动的大型冰川记录提供了独特的机会。最后，冰碛的良好保存和不稳定巨石的抵抗岩性为宇宙成因表面暴露测年提供了理想的目标。我们建议结合传统和先进的研究方法来研究尤因塔山脉的晚第四纪冰川和古气候记录，以实现以下目标：1）确定末次盛冰期期间和之后尤因塔山脉冰川作用的范围和时间。这项工作将涉及 (1) 对尤因塔山脉南翼的地表地质进行详细的野外和航空摄影测绘 (2) 对尤因塔山脉西部、中部和东部末次盛冰期沉积的冰碛进行宇宙成因表面暴露测年，以及 (3) 检索和研究该山脉北坡和南坡被退行冰碛堵塞的湖泊中的湖泊沉积物岩心。 2) 重建最新的更新世古气候来自尤因塔山脉的冰川记录。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。我们将利用最新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；这将有助于对尤因塔山脉的末次盛世古气候进行独特的测定。 更广泛的影响 本提案中概述的研究将产生超出追求核心科学目标的益处。首先，它将进一步促进阿什利国家森林 (ANF) 和威斯康辛大学麦迪逊分校之间的持续关系。由于国家森林的公共利用和更加集约化的管理，ANF 的主管对林地的地质历史产生了更大的兴趣，并在过去 8 年里支持尤因塔山脉的研究生研究（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；参见支持信）。第二，博士。学生 B. Laabs 将参加新的 NSF 研究教学整合中心 (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科学教授。他将参加 CIRTL 课程和研讨会，重点关注如何有效利用研究方法在大学课堂上传播科学知识。拉布斯将成为第一批获得证书的研究生之一，该证书承认为学术界的职业生涯做好了准备，并将 NSF-威斯康辛大学-麦迪逊分校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）以他在尤因塔斯大学的研究生工作为基础，并开始让本科生参与他目前对该地区第四纪晚期历史的研究。拟议的研究为三个地质学专业的高年级学生提供了就总体研究目标的各个方面攻读本科论文的机会（有关更多信息，请参阅 RUI 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).