SusChEM: Exploring Links Among U, Fe, and Hydrocarbon Movement in the Paradox Basin, Colorado Plateau

帕拉迪纳盆地和科罗拉多高原的其他沉积盆地拥有许多重要的矿产和碳氢化合物资源，包括铁、铜、钴、锰、银以及石油和天然气，并以拥有世界上最大的铀生产省之一而闻名。在Parkland盆地进行的新的普查地质研究揭示了铀矿化、油气运移以及铁和其他元素的流动性之间意想不到的空间和地层联系。这些联系表明，需要一种新的铀沉积模式：一种石油，可能还有天然气，导致铀可能在混合带中局部捕获的模式，与铀被原生于主岩的有机质捕获的流行模式相反。这一新的假设并不排除其他可能性，但它预测，较大的矿床可能具有较高的品位，并具有明显和更局部的分布。铁和其他元素同时重新分布的证据表明，同一种流体移动了许多元素;这种元素重新分布为流体地球化学和运动提供了线索。该项目将促进对Parabolic和其他沉积盆地中金属运动和物质运输的基本地球化学认识，并可能为在拥有世界级矿产资源的地区发现矿产提供新的方法。沿着帕拉迪纳盆地100多km长的里斯本谷盐壁，选择了五个焦点点沿着进行野外绘图、岩心测井、岩相学、流体包裹体以及元素和同位素分析。焦点地点代表了不同的地层和构造环境，范围从盆地的中心深部到边缘，但都显示出铀矿化、铁的流动性和漂白或其他碳氢化合物的证据。蚀变矿物、岩相学和全岩分析的绘图将用于记录从单个存款到次区域尺度上的铁、碱和贱金属富集和贫化的分布和共生。研究人员将把这些观察结果与铀和相关（钒、铜）矿化的分布、演化和时间序列以及油气藏和迁移路径的位置联系起来。再加上流体包裹体和蚀变矿物的同位素分析以及地球化学建模，以评估流体特征和来源，这些数据将能够系统地测试含金属盆地卤水、碳氢化合物和局部结构和岩石类型之间的相互作用-例如，U、Fe和碳氢化合物的运动和沉积是否代表单一短寿命系统的不同方面，代表了一个系统在很长一段时间内的演化，或者是由多个不相关的叠加事件产生的。这是一个综合的方法来研究质量之间的联系，在帕拉迪诺盆地，这可以应用在科罗拉多高原和世界各地的传输现象的第一步，了解地质和地球化学演化的重要资源省份，探索和管理资源开发。

The Paradox basin and other sedimentary basins of the Colorado Plateau host many significant mineral and hydrocarbon resources, including iron, copper, cobalt, manganese, silver, and oil and gas, and are best known for hosting one of the world's great uranium-producing provinces. New reconnaissance geological studies in the Paradox basin revealed unexpected spatial and stratigraphic connections between uranium mineralization, hydrocarbon migration, and mobility of iron and other elements. These connections suggest that a new model for uranium deposition is required: one where oil, and possibly natural gas, leads to localized trapping of uranium perhaps in mixing zones, in contrast to the prevailing model where uranium is trapped by organic matter that is indigenous to the host rock. This new hypothesis does not preclude the alternatives, but it predicts that the larger deposits may have higher grades and have a distinct and more localized distribution. Evidence for concurrent redistribution of iron and other elements suggests that the same fluids move many elements; such element redistribution gives clues to fluid geochemistry and movement. This project will advance the fundamental geochemical understanding of metal movement and mass transport in the Paradox and other sedimentary basins and it may provide novel approaches to mineral discovery in a region with world-class mineral resources. Five focus sites along the 100+ km-long Lisbon Valley salt wall in the Paradox Basin have been selected for field mapping, core logging, petrographic, fluid inclusion, and elemental and isotopic analyses. The focus sites represent diverse stratigraphic and structural settings and range from the deep central part of the basin to the fringes, but all show uranium mineralization, iron mobility, and bleaching or other evidence of hydrocarbons. The mapping of alteration minerals, petrography, and whole-rock analyses will be used to document the distribution and paragenesis of iron, alkali, and base metal enrichment and depletion at scales from the single deposit to the sub-region. The investigators will correlate these observations with the distribution, evolution, and temporal sequence of uranium and related (vanadium, copper) mineralization and the loci of hydrocarbon reservoirs and migration paths. Coupled with fluid inclusion and isotopic analyses of alteration minerals and geochemical modeling to evaluate fluid characteristics and sources, these data will enable a systematic test of the interplay between metal-bearing basinal brines, hydrocarbons, and local structures and rock types - e.g. whether the movement and deposition of U, Fe, and hydrocarbons represent different facets of a single short-lived system, represent the evolution of a single system over a long time, or were produced by multiple unrelated superimposed events. This is a first step toward an integrated approach to studying linkages among mass transport phenomena in the Paradox Basin, which can be applied on the Colorado Plateau and worldwide both to understanding the geological and geochemical evolution of important resource provinces and to exploring and managing resource development therein.