Sedimentologic and Diagenetic History of the Mission Canyon Formation (Mississippian) and Stratigraphic Equivalents, Southwestern Montana and East-Central Idaho and Determination of Rare Earth Element Abundances in Diagenetic Carbonates: Technical Progres

摘要

The Mission Canyon Formation in southwestern Montana and its stratigraphic equivalents in east-central Idaho form an important stratigraphic sequence which was deposited during a critical stage in the evolution of the western continental margin of North America. This progress report presents data acquired since the beginning of DOE sponsorship of research on this sequence. Preliminary interpretations are presented in this report where the data set allows. This study will provide important information concerning the distribution and geometries of various lithofacies in the Mission Canyon Formation and its stratigraphic equivalents. The study area lies along the trend of the Mississippian platform margin and covers the Mississippian platform margin-to-basin transition. Our detailed sedimentologic studies have allowed us to understand the evolution of the platform margin-to-basin transition, an integrated petrographic and geochemical study of the Mission Canyon Formation is being carried out within the sedimentologic context established by field studies. Petrography and geochemical microanalyses provide nearly complete chemical characterization of diagenetic carbonates. These data are being used to interpret extent of diagenetic alteration, sources of ions incorporated into cements, and paleohydrology of diagenetic fluids. 5 refs. (ERA citation 14:027334)