Sequence Stratigraphy, Third-Order Accommodation Events and Related Diagenetic History of the Middle Cambrian Bonanza King Formation, Southern Great Basin

拟议的研究涉及一个组合序列 旋回被动边缘地层和成岩作用分析 中晚寒武世Bonanza King组碳酸盐岩 大盆地南部（加州和内华达州）。 形成 在300 - 1350米之间， 从克拉通边缘到陆棚边缘和斜坡基底相的楔。 富矿王由200米尺度的碳酸盐岩旋回组成 提供了中晚寒武世一个显著的条带记录 三阶相对海平面振荡。 初步结果表明，四个半三阶 序列可以被识别并绘制出整个博南扎国王 平台 厚的潮下带周期的间隔似乎 描述了海侵体系域、薄的 潮周旋回是高位体系域的特征， 显示出零星暴露迹象的潮周周期带 可能显示层序边界带。 旋回内丰度 从克拉通边缘到克拉通边缘， 外平台。 层序界面带及上部旋回 高位体系域以白云岩为主， 海侵体系域和低位体系域 保留着丰富的石灰岩。 本研究的目的有四个：1）剖析 碳酸盐岩地层层序内部解剖 出露条件好，露头面积大，旋回性强 作为数据库。 可预测 周期叠加模式和跨平台趋势的变化 将被用来确定组成系统的大片和边界 不整合 2)开发可靠的中晚寒武世 与其他已发表曲线的比较适应曲线， 确定海平面变化对层序发育的控制程度。 3)记录海平面波动的影响， 富矿王碳酸盐岩早期成岩作用的频率。四、 评价结构、岩石物理和地球化学变化， 发生在流体-岩石相互作用的早期成岩相 整个葬礼。 该研究将层序地层学与海洋- Bonanza King组记录的水平和成岩历史 也是首次尝试破译 科迪勒拉被动边缘的早古生代碳酸盐岩。

The proposed research involves a combined sequence stratigraphic and diagenetic analysis of cyclic passive margin carbonates of the Middle to Late Cambrian Bonanza King Formation of the southern Great Basin (California and Nevada). The formation ranges from 300 to 1350 meters and forms a westward-thickening wedge from craton margin to shelf-edge and base-of-slope facies. The Bonanza King is composed of 200 meter-scale carbonate cycles that provide a remarkable strip record of Middle to Late Cambrian third-order relative sea-level oscillations. Preliminary results suggest that four and a half third-order sequences can be recognized and mapped out across the Bonanza King platform. Intervals of thick subtidal cycles appear to characterize the transgressive systems tracts, intervals of thin peritidal cycles characterize the highstand systems tracts and thin zone of peritidal cycles exhibiting evidence of sporadic exposure probably manifest sequence boundary zones. Intracyclic abundance of early dolomite decreases systematically from craton margin to outer platform. Cycles in sequence boundary zones and upper highstand systems tracts are dominantly dolomite whereas cycles in transgressive systems tracts and lower highstand systems tracts retain abundant limestone. The objectives of the research are fourfold: 1) Dissect the internal anatomy of carbonate stratigraphic sequences using the excellent exposures, broad outcrop area and extraordinary cyclicity of the Bonanza King Formation as the data base. Predictable variations in cycle stacking patterns and cross-platform trends will be used to identify the component systems tracts and bounding unconformities. 2) Develop a reliable Middle to Late Cambrian accommodation curve of comparison to other published curves to determine the degree of eustatic control on sequence development. 3) Document the effects of sea-level fluctuations of all frequencies on early diagenesis of Bonanza King carbonates. 4) Evaluate the textural, petrophysical and geochemical changes that occur in early diagenetic facies during fluid-rock interaction throughout burial. This study integrates the sequence stratigraphy with the sea- level and diagenetic history recorded in the Bonanza King Formation and is the first major attempt to decipher the diagenetic history of early Paleozoic carbonates of the Cordilleran passive margin.