Ordovician K-bentonite Stratigraphy of the Central and Southern Appalachians: Implications for Regional Strati- graphic and Tectonic Synthesis

PI将研究中大陆东部晚奥陶世大量钾质膨润土层的分布、地层对比、化学和古构造背景。工作将集中在阿巴拉契亚山脉的中部和南部，在那里以前的研究表明洛克兰德的Deicke和米尔布里格的k -膨通岩广泛存在。建立这些地层的相关性将确定几个奥陶纪年代地层表面，从密西西比河谷延伸到密歇根盆地和辛辛那提拱门，再到阿巴拉契亚盆地。这些地层将为克拉通内部台地碳酸盐岩和硅质碎屑岩相对比提供区域时间线，通过斜坡和斜坡碳酸盐岩沉积，再到东部山谷和山脊的深水和红层相。化学数据将根据目前的岩石构造模型进行评估，以解释源火山的构造背景。研究结果将与岩石地层和生物地层资料相结合，绘制北美奥陶系主要钾基膨润土层的区域年代地层、等厚图和等化学图。

PI's will study the distribution, stratigraphic correlation, chemistry and paleotectonic setting of extensive Late Ordovician K-bentonite beds in the eastern midcontinent. Work will focus on the central and southern Appalachians where previous studies indicate the Rocklandian Deicke and Millbrig K-bentonites are widespread. Establishing the correlation of these beds will define several Ordovician chronostratigraphic surfaces extending from the Mississippi Valley across the Michigan Basin and Cincinnati Arch and into the Appalachian Basin. These beds will provide regional time lines for facies correlation from platform carbonates and silliciclastics in the interior of the craton through ramp and slope carbonate deposits to both deep-water and redbed facies of the eastern Valley and Ridge. Chemical data will be evaluated according to current petrotecotnic models to interpret the tectonic setting of the source volcanoes. Results will be combined with lithostratigraphic and biostratigraphic information to produce regional chronostratigraphic, isopach and isochemical maps of the principal Ordovician K-bentonite beds in North America.