Environments of Sedimentation and Controls on Diagenesis of the Creede Fm., Colorado

渐新世克里德沉积岩和火山岩 将对地层进行调查，以评估范围， 海岸带内沉积环境的演化， 在intracaldera设置成岩作用和蚀变的控制。 选择克里德地层进行本研究是因为 相对发育不全的火山岩内 与一个大的复活的破火山口， 克里德地区众所周知的火山地层学和年代学， 也有机会测试和贡献给那些经过充分研究的 克里德热液模型。 与以前的研究相比， intracaldera沉积岩，这项研究将侧重于评估 盆地范围内的沉积、原生 火山碎屑岩、热液岩及自生矿物 化学和分布。 这些数据将用于：1） 了解沉积过程和沉积物 分布格局发生在一个intra-caldera盆地;和2） 评估沉积环境的相对控制， 热液活动、有机碳分布与盆地 水文学对火山碎屑岩成岩作用的影响。 的 该项目的成果将提供一个工作模式， 沉积作用和成岩作用， 并允许评估克里德地层的作用 沉积物可能在信经的演变中发挥了作用 热液系统 总的来说，结果将有助于 我们对破火山口演化和热液系统的理解 与破火山口有关，并提供有价值的基线数据， 其他intracaldera沉积序列的评价。

The sedimentary and volcaniclastic rocks of the Oligocene Creede Formation will be investigated in order to assess the range and evolution of intracaldera sedimentary environments, and the controls on diagenesis and alteration in an intracaldera setting. The Creede Formation was chosen for this study because of the extensive exposures of relatively underformed intracaldera sedimentary rocks associated with a large resurgent caldera, the well known volcanic stratigraphy and chronology of the Creede area, and the opportunity to test and contribute to the well-studied Creede hydrothermal model. In contrast to previous studies of intracaldera sedimentary rocks, this study will focus on evaluating the basin-wide field relationships among sedimentary, primary pyroclastic, and hydrothermal rocks, as well as authigenic mineral chemistry and distribution. These data will be used to: 1) develop an understanding of depositional processes and sediment distribution patterns occurring in an intracaldera basin; and 2) assess the relative controls of the depositional environment, hydrothermal activity, organic carbon distribution, and basin hydrology on the diagenesis of the volcaniclastic rocks. The results of this project will provide a working model for sedimentary deposition and diagenesis in an intracaldera setting, as well as allow an assessment of the role the Creede Formation sediments may have played in the evolution of the Creed hydrothermal system. In general, the results will contribute to our understanding of caldera evolution and hydrothermal systems associated with calderas, and provide valuable baseline data for evaluation of other intracaldera sedimentary sequences.