A Petrologic and Geochemical Study of Authigenic/Diagenetic Clay Minerals in Upper Mississippian Platform-Tidal Flat Carbonate Rocks

密西西比盆地上部-潮坪碳酸盐岩自生/成岩粘土矿物的岩石学和地球化学研究

• 批准号: 8816092
• 负责人: Charles Weaver
• 金额: $ 15.84万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-01-01 至 1991-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8816092&HistoricalAwards=false
• 关键词: Petrologic; Geochemical; Study; Authigenic; Diagenetic

A survey of the literature indicates that, compared to shales and sandstones, relatively little micropetrographic work (SEM-EDX, electron probe) has been done on authigenic and diagenetic clay minerals in carbonate rocks. This project is a micropetrographic investigation of the Upper Mississippian shelf-tidal flat carbonates, which occur in excellent exposures along the edge of the Cumberland Plateau (TN). These rocks contain a wide variety of possible authigenic/diagenetic clay minerals (Ch/S, Ch/V, corrensite, vermiculite, illite, I/S). A preliminary SEM-EDX study (Fig. 1-3) confirms the presence of authigenic/diagenetic I/S (4:1) in the interior of calcite oolites. The study will concentrate on the Upper Mississippian carbonates and establish the genetic relation of the Mg clays and K clays to calcite, dolomite and the various shallow carbonate environments. In addition to chemical, mineralogical, and petro- graphic data will be obtained on spatial and volume data so that mass balance calculations can be made for Mg and other ions. In addition to obtaining information of the origin of the clay minerals, we will obtain information on the factors effecting the partitioning of Mg between silicate and carbonate minerals. The goal of this research is to determine the nature, significance of clay mineral reactions in carbonate rocks, shedding light on diagenetic processes.

文献调查表明，与页岩和砂岩相比，对碳酸盐岩中自生和成岩粘土矿物的显微岩相学工作（SEM-EDX、电子探针）相对较少。 该项目是对密西西比河上游陆架潮坪碳酸盐岩的显微岩相研究，这些碳酸盐岩位于坎伯兰高原 (TN) 边缘的良好暴露区域。 这些岩石含有多种可能的自生/成岩粘土矿物（Ch/S、Ch/V、Corrensite、蛭石、伊利石、I/S）。 初步的 SEM-EDX 研究（图 1-3）证实了方解石鲕岩内部存在自生/成岩 I/S (4:1)。 该研究将集中于密西西比河上游碳酸盐岩，并建立镁粘土和钾粘土与方解石、白云石和各种浅层碳酸盐环境的成因关系。 除了化学、矿物学和岩相学数据外，还将获得空间和体积数据，以便可以对镁和其他离子进行质量平衡计算。 除了获得粘土矿物来源的信息外，我们还将获得影响镁在硅酸盐和碳酸盐矿物之间分配的因素的信息。 这项研究的目的是确定碳酸盐岩中粘土矿物反应的性质和意义，为成岩过程提供线索。