(GRGC) Cyclostratigraphy and Carbonate Platform Evolution, Middle Cretaceous, Northeastern Mexico

本研究拟对墨西哥东北部的中白垩世（Albian） Coahuila碳酸盐岩台地进行研究，这是一个横向扩展的被动边缘台地，代表了墨西哥湾沿岸地区碳酸盐岩沉积的最后一个主要时期。提出的研究的第一个目标是确定中白垩纪相对海平面在104至106年时间尺度上的变化历史。该项目的这一方面将涉及使用高分辨率层序地层学和旋回地层学来记录跨平台关系，并解释Coahuila平台的时间演化。第二个目标是确定墨西哥东北部Albian浅海相碳酸盐岩中米兰科维奇尺度旋回发育的程度；米兰科维奇周期在意大利同时期的阿尔比亚深海沉积物中得到了明确的承认。第三个目标是利用观测到的场关系来约束二维计算机模型，这样就可以定量地估计墨西哥东北部的阿尔比时调节变化的速率、频率和幅度。拟议的旋回地层学和层序地层学研究是墨西哥东北部白垩纪中期更大规模合作的一部分，目前正在进行中，涉及一个多学科的生物地层学家和磁地层学家团队，该团队与白垩纪资源、事件和节律工作组的Albicore项目有关。拟议的研究预计将产生几项重大贡献。在旋回地层学和层序地层学结果与合作研究人员所获得的精细年代地层学分辨率相结合后，将有可能获得更精确的阿拉边沉积层序全球对比。改进后的地质年代学代表了详细层序地层学和计算机模拟与生物地层学和磁地层学的结合，将允许对全球过程的速率和持续时间进行定量估计，并加强对区域到全球范围的控制层序沉积机制（构造作用、海水沉降、环境变化）的解释。这项跨学科研究在Coahuila平台上的进一步应用是，将开发一个新的模型，用于与全球其他Albian平台进行比较，包括中东具有重要经济意义的碳酸盐岩平台。

9417872 Osleger The proposed research intends to investigate the Mid-Cretaceous (Albian) Coahuila carbonate platform of northeastern Mexico, a laterally-extensive, passive-margin platform that represents the final major episode of carbonate sedimentation in the Gulf Coast region. The first objective of the proposed research is to determine the history of Mid-Cretaceous relative sea-level changes at time scales ranging from 104 to 106 years. This aspect of the project will involve the use of high-resolution sequence stratigraphy and cyclostratigraphy to document cross-platform relationships and interpret the temporal evolution of the Coahuila platform. The second objective is to determine the extent to which Milankovitch-scale cyclicity is developed in Albian shallow-marine carbonates of northeastern Mexico; Milankovitch periodicities have been unequivocally recognized in coeval Albian deep-sea sediments in Italy. The third objective is to use the observed field relationships to constrain two-dimensional computer models so that rates, frequencies, and magnitudes of accommodation change through Albian time can be quantitatively estimated for northeastern Mexico. The proposed cyclostratigraphic and sequence stratigraphic research is part of a larger-scale collaborative effort on the Mid- Cretaceous of northeastern Mexico currently underway involving a multidisciplinary team of biostratigraphers and magnetostratigraphers associated with Project Albicore of the Cretaceous Resources, Events and Rhythms working group. The proposed research is expected to result in several major contributions. More precise global correlations of Albian depositional sequences should be possible after the cyclostratigraphic and sequence stratigraphic results are integrated with the refined chronostratigraphic resolution attained by the collaborative researchers. The improved geochronometry, representing the merger of detailed sequence stratigraphy and computer modeling with bio - and magnetostratigraphy, will permit the quantitative estimation of rates and durations of global processes, and enhance interpretations of the regional- to global- scale mechanisms governing sequence deposition (tectonism, eustasy, environmental change). A further application of this interdisciplinary research on the relatively-uninvestigated Coahuila platform is that a new model will be developed for comparison with other Albian platforms worldwide, including the economically-significant carbonate platforms of the Middle East.