RUI: Integrated Stratigraphic and Sedimentological Analysis of the Cambro-Ordovican Inner Shelf, Colorado

9419141我认为，动物群更替的间隔，包括重大物种灭绝，与最终可能支配这些事件的各种沉积和构造过程之间的关系，对于全面了解地层记录至关重要。需要在陆上-近海剖面中整合所有区域的沉积学、古生物学和地层学数据，以便对系统动力学进行完整的分析。寒武纪-奥陶系界线段记录了几次动物群更替事件，包括在科迪洛德斯牙形刺带底部的一次重大灭绝，由于生物地层分辨率较差，在北美内部碎屑带沉积中通常未被识别或未被保存。来自记录充分的寒武纪-奥陶纪平台、大盆地近海地区和其他地方的沉积学和生物地层学数据已被用来提出动物灭绝的过程-反应模型，在许多情况下，这包括传说中的狂喜“事件”。不幸的是，关于动物群更替间隔与沉积和构造事件的关系，很少或根本没有来自同时代近缘肉体沉积的信息，这可以用来检验物种灭绝的原因或拟议的狂喜事件的全球相关性。科罗拉多州中西部寒武系-奥陶系硅质碎屑岩和碳酸盐肉质岩暴露良好且厚度较厚，为评估古北美寒武系-奥陶系古地理区域在动物群更替事件期间和之间的沉积体系的时空变化提供了一个极好的机会。提出了一个为期两年的沉积学和地层学研究项目，其中利用牙形刺生物地层学和沉积学标准识别不整合岩将首次使科罗拉多州寒武纪-奥陶系建立详细的层序地层格架。将这些沉积物的系统动力学与记录充分的舷外演替进行对比，将有助于更全面地了解动物群和沉积系统演化之间的相互作用。

9419141 Myrow The relationship between intervals of faunal turnover, including major extinctions, and various depositional and tectonic processes which may ultimately govern these events, is critical to the holistic understanding of the stratigraphic record. Integration of sedimentological, paleontological, and stratigraphic data from all regions in an onshore-offshore profile are required for a complete analysis of system dynamics. The Cambro-Ordovician boundary interval, which records several faunal turnover events including a major extinction at the base of the Cordylodus proavis conodont zone, is generally unrecognized or not preserved in inner detrital belt deposits in North America because of poor biostratigraphic resolution. Sedimentological and biostratigraphic data from well-documented Cambro-Ordovician platform and offshore areas of the Great Basin and elsewhere have been used to propose processes-response models for faunal extinctions, which in many cases include puported ecstatic "events". Unfortunately, little or no information exists from coeval proximal carnal deposits concerning the relationship of intervals of faunal turnover with depositional and tectonic events, which can be used as a test of the cause of extinctions or the global correlation of proposed ecstatic events. Well-exposed and thick Cambro-Ordovician siliciclastic and carbonate carnal rocks in central and western Colorado provide an excellent opportunity to assess spatial and temporal changes in depositional systems during and between faunal turnover events for this poorly understood and biostratigraphically unconstrained paleogeographic region in the Cambro-Ordovician of ancient North America. A two-year project is proposed for a sedimentological and stratigraphic study in which the recognition of unconformitites using conodont biostratigraphy and sedimentological criteria will for the first time enable construction of a detailed sequence-stratigraphic framework for the Cambro-Ordovician of Colorado. Co mparison of systems dynamics for these deposits with well-documented outboard successions will contribute to a more complete understanding of the interplay between the evolution of faunal communities and depositional systems.