Collaborative Research: Clinker Geochronology and Geomorphic Evolution of the Powder River Basin, Wyoming

合作研究：怀俄明州粉河盆地的熟料地质年代学和地貌演化

• 批准号: 0518818
• 负责人: Peter Reiners
• 金额: $ 12万
• 依托单位: Yale University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-10-01 至 2006-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0518818&HistoricalAwards=false
• 关键词: Collaborative; Research; Clinker; Geochronology; Geomorphic

Clinker, rock metamorphosed by natural coal burning, has formed in the Powder River Basin (and other areas of the Rocky Mountains) since at least Pliocene. Clinker dominates the topographic form of many of the basins in which it is found, because it is more resistant to weathering than surrounding unaltered bedrock. It also preserves a record of the spatial-temporal patterns of fluvial incision, lateral backwasting, and plateau formation in these landscapes, because coal only burns when close to the surface, above the water table and ventilated with surface oxygen. Using (U-Th)/He ages of detrital zircons that are reset during clinker formation, we will map the patterns of coal burning and shallow exhumation in detail in several regions of the PRB in Wyoming and Montana, as well as characterize clinker ages over a broader scale throughout the basin. Model predictions of clinker age-patterns in individual drainages and across the landscape suggest that our results will be able to discriminate between at least some of these possible climatological or tectonic mechanisms driving landscape evolution. This work will form the basis of collaborative research between Reiners and Riihimaki, as well as individuals in the BLM and the Northern Cheyenne Tribe, and undergraduate students from Yale and Bryn Mawr.

熟料是由天然燃煤燃烧变形的岩石，自至少上新世以来就在粉末河盆地（以及落基山脉的其他地区）形成。熟料占主导地位的许多盆地的地形形式，因为它比周围的未改变的基岩更能抵抗风化。它还保留了这些景观中河流切口，侧向吹扫和平稳形成的空间周期模式的记录，因为煤在靠近地面（地面上方），地下水位上方并用表面氧气通风时才燃烧。使用（u-th）/He年龄在熟料形成过程中重置的碎屑锆石，我们将在怀俄明州和蒙大拿州的PRB的几个区域中详细绘制燃烧燃烧和浅灌溉的模式，并在整个Basin范围内更广泛地绘制熟料年龄的熟料。熟料年龄patterns在单个排水和整个景观中的模型预测表明，我们的结果将能够区分至少某些可能的气候或构造机制驱动景观演变。这项工作将构成Reiners和Riihimaki之间的合作研究的基础，以及BLM和Cheyenne Tribe的个人，以及耶鲁大学和Bryn Mawr的本科生。