Stable Isotope Stratigraphy of the Miocene Monterey Formation, California: Testing the Monterey Hypothesis

PI将对加州中新世蒙特利组那不勒斯海滩的出露进行沉积学、稳定同位素和生物地层学研究。蒙特雷组沉积发生在全球变化的一个重要时期，那不勒斯海滩段的保存质量代表着获得详细的古环境记录的重要机会。蒙特利组和环太平洋周围相关沉积物中大量有机碳的滞留与早中新世深海13C的升高以及通过二氧化碳减少而导致的全球变冷有关，被称为“蒙特利假说”。这项拟议的工作将通过评估蒙特利组中增强的富有机沉积与深海13C峰值之间的同步性来检验蒙特利假说的推论，这需要比现有的生物地层学和化学地层学提供的更好的年龄控制。稳定的同位素地层学有可能将富有机沉积与那不勒斯海滩记录中的13C最大值直接比较，或与深海13C最大值进行对比。拟议的工作将解决的中心问题是：稳定的同位素地层学能否加强蒙特利组的国际相关性，并有助于检验蒙特利假说？环太平洋边缘盆地沉积层序与全球古海洋学变化有何关系？PI将在对底栖有孔虫动物群进行定量分析的基础上，建立稳定的同位素地层学和详细的古环境历史。将所得到的动物群和稳定同位素时间序列与沉积学信息相结合，将大大加强与环太平洋中新世层序的对比，并阐明富有机质沉积与早、中中新世全球海洋事件的关系。

PI will conduct sedimentologic, stable isotopic and biostratigraphic studies of the Naples Beach exposure of the Miocene Monterey Formation, California. Monterey Formation deposition occurred over a significant interval of global change, and the preservational quality of the Naples Beach section represents an important opportunity for obtaining detailed paleoenvironmental records. The sequestering of great quantities of organic carbon in the Monterey Formation and correlative deposits around the Pacific Rim has been linked to an early to middle Miocene increase in deep-sea 13C, and to global cooling through drawdown of pCO2, termed the "Monterey Hypothesis". The proposed work will test a corollary of the Monterey Hypothesis by evaluating the synchroneity between intervals of enhanced organic-rich deposition in the Monterey Formation and deep-sea 13C maxima, which requires better age control than the existing biostratigraphy and chemostratigraphy provide. Stable isotopic stratigraphy has the potential for direct comparison of intervals of organic- rich deposition with 13C maxima in the Naples Beach record, or for correlation to deep-sea 13C maxima. Central questions which the proposed work will address are: Can stable isotopic stratigraphy enhance international correlation of the Monterey Formation and aid in testing the Monterey Hypothesis? What is the relationship between sedimentary sequences in marginal basins of the Pacific Rim to global paleoceanographic changes? PI will develop a stable isotopic stratigraphy and a detailed paleoenvironmental history based on quantitative analysis of benthic foraminiferal faunas. integration of the resulting faunal and stable isotopic time series with sedimentologic information will greatly enhance correlation to Miocene sequences of the Pacific Rim and illuminate the relationship between organic-rich deposition and global oceanographic events in the early to middle Miocene.