Sedimentation and Diagenesis of the Creede Fm., CO: Subsurface Evaluation and Correlation with Outcrop Studies

研究和勘探岩心中所遇到的渐新世Creede组（San Juan Mountains, Colorado）的沉积和火山碎屑地层，以评价在裂孔内环境下的沉积环境和对成岩作用的控制。该项目将补充正在进行的克里德组沉积环境和成岩作用的地表研究。将根据露头研究建立的标准确定沉积环境，并根据沉积相收集样品组。岩石学和矿物学检查也将用于确定成岩事件的顺序。岩心和地表剖面的地层对比将为解释沉积模式和成岩作用的跨河变化提供一个框架。研究结果将提供(1)更完整的破火山口内环境沉积模型；(2)更好地理解Creede沉积后复杂的成岩系统；(3)破火山口护城河盆地构造和沉积演化建模的约束条件。(4)为验证克里德沉积在克里德地区成矿流体演化中起主要作用的假设建立了沉积学框架。

Sedimentary and volcaniclastic strata of the Oligocene Creede Formation (San Juan Mountains, Colorado) encountered in research and exploration cores will be examined in order to evaluate environments of sedimentation and controls on diagenesis in an intracaldera environment. The project will complement ongoing surface study of depositional environments and diagenesis of the Creede Formation. Depositional environments will be identified based on criteria established from outcrop study, and a sample suite based on sedimentary facies will be collected. Petrologic and mineralogic examination will also be used to identify the sequence of diagenetic events. Stratigraphic correlation of core and surface sections will provide a framework for interpreting cross-moat changes in depositional patterns and diagenesis. The results will provide (1) a more complete model for sedimentation in an intracaldera environment, (2) a better understanding of the complex diagenetic system that operated following Creede deposition, (3) constraints for modeling the structural and depositional evolution of caldera moat basins, and (4) a sedimentologic framework for testing the hypothesis that Creede sediments played a major role in the evolution of fluids responsible for Creede district mineralization.