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

熟料是通过自然燃煤而变质的岩石，至少自上新世以来就在鲍德河盆地(和落基山脉的其他地区)形成。熟料在许多发现熟料的盆地的地形形态中占主导地位，因为它比周围未改变的基岩更耐风化。它还保存了这些景观中河流切割、侧向回流和高原形成的时空模式的记录，因为煤炭只有在接近地表、高于地下水位并在地表氧气通风的情况下才会燃烧。利用在熟料形成过程中重新设定的碎屑锆石(U-Th)/He年龄，我们将详细绘制怀俄明州和蒙大拿州PRB几个地区的燃煤和浅层折返模式，并在整个盆地更大范围内表征熟料年龄。对单个流域和整个景观中熟料年龄模式的模型预测表明，我们的结果将能够区分这些可能驱动景观演变的气候或构造机制中的至少一些。这项工作将成为Reiners和Riihimaki，以及BLM和Northern Cheyenne部落的个人，以及耶鲁大学和Bryn Mawr本科生之间合作研究的基础。

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.