Collaborative Research: Reconstructing the Origins of the Colorado River: An Integrative Study of the Miocene-Pliocene Bouse Formation

尽管经过了近一个世纪的研究，但控制浩瀚的科罗拉多河发源的条件仍然鲜为人知，也存在激烈的争论。该项目试图通过对Bouse地层的多学科研究来重建科罗拉多河的起源，Bouse地层是一种复杂的沉积沉积物，在约6.0至450万年前的河流起源期间积累在山谷的下游。这项研究得益于大学教授和学生、州和联邦机构科学家、县博物馆古生物学家和当地高中教师的合作。PI将使用综合数据集来确定Bouse地层是在微咸水的海洋河口形成的，还是在与海洋隔离的大型内陆湖泊形成的，这是了解河流起源的关键区别。这项研究还探索了科罗拉多河的水第一次流入大海的时间和方式。假说将通过地层构造学、沉积学、碳酸盐地球化学(包括C、O、Sr和S同位素)和地质年代学的研究来验证。假设检验强调放射性成因和稳定的同位素数据与主要和微量元素化学在精确的地层和构造框架内的相互关系。PI将举办两个研讨会：一个是让广泛的地球科学家社区参与进来，另一个是规划未来的科学钻探提案。

Despite nearly a century of study, the conditions that controlled initiation of the mighty Colorado River remain poorly understood and vigorously debated. This project seeks to reconstruct the origins of the Colorado River through multidisciplinary study of the Bouse Formation, a complex sedimentary deposit that accumulated in the lower reaches of the valley during river initiation between ~ 6.0 and 4.5 million years ago. The study benefits from collaborations among university professors and students, state and federal agency scientists, a county museum paleontologist, and a local high school teacher. The PI's will use integrated datasets to determine if the Bouse Formation formed in a brackish marine estuary or a large inland lake isolated from the ocean, a key distinction for understanding the origins of the river. This study also explores when and how waters of the Colorado River first reached the sea. Hypotheses will be tested through study of stratigraphic architecture, sedimentology, carbonate geochemistry (including C, O, Sr, and S isotopes), and geochronology. Hypothesis tests emphasize cross-correlation of radiogenic and stable isotope data with major and trace-element chemistry in a precise stratigraphic and structural framework. The PI's will run two workshops: one to engage a broad community of geoscientists, and one to plan a future scientific drilling proposal.