A Comparative Study of Fe-P Mineralization

本项目建议研究两个领域的对比铁磷 北方大盆地中生代中期的成矿作用， 将它们与正在进行的合作研究的结果进行比较， 密苏里州东南部的元古代铁磷矿床。 领域 选择的研究有：（1）洪堡火山柱（内华达州西部）; (2)科尔特斯山脉（内华达州中部）;（3）花岗岩- 圣弗朗西斯山脉的流纹岩。 计划： (1)表征选定的矿床、相关的蚀变，以及 （2）评价了成矿条件和成矿物质来源; 成分来源，（3）调查相似性的原因 和差异。 选择性绘图和样本采集将 随后进行岩相学和地球化学研究。 该项目的密苏里州部分将与 密苏里州DLGS和美国地质勘探局了解中部大陆“奥林匹克 大坝”系统。 本文通过放射性同位素（Sr、Nd、Pb）分析， 特征样品将用于：（1）改进地质年代学 （2）有助于解决成分来源， 成矿机制 区域稳定同位素研究（O， H，S）和选定的放射性同位素分析将调查 热液系统的时间、分布和强度， 与矿化的关系。 密苏里州和内华达州 调查工作将联合收割机两项相辅相成的工作结合起来， 定量解释铁磷成因的长期目标 存款

This project proposes to examine two areas of contrasting Fe-P mineralization in the mid-Mesozoic of the northern Great Basin and compare them with results from ongoing cooperative studies of the Proterozoic Fe-P deposits in southeastern Missouri. Areas for selected study are: (1) the Humboldt Lopolith (western Nevada); (2) the Cortez Mountains (central Nevada); and (3) the granite- rhyolite terrane of the St. Francois Mountains. It is planned to: (1) characterize selected deposits, associated alteration, and related magmatism, (2) evaluate the conditions of formation and the sources of components, and (3) investigate reasons for similarities and differences. Selective mapping and sample collection will be followed by petrographic and geochemical work. The Missouri portion of this project extends a joint effort with the Missouri DLGS and USGS to understand mid-continent "Olympic Dam" systems. Radiogenic isotopic analyses (Sr, Nd, Pb) from well- characterized samples will be used to: (1) improve geochronometry of mineralization, and (2) help resolve sources of components and mechanisms of ore formation. Regional stable-isotope studies (O, H, S) and selected radiogenic isotopic analyses will investigate the timing, distribution, and intensity of hydrothermal systems and their relationship to mineralization. The Missouri and Nevada investigations combine two complementary ongoing efforts with the long-term aim of quantitatively interpreting the genesis of Fe-P deposits.