Diatom Biostratigraphy & Paleoceanography of the Santa Cruz Mudstone

圣克鲁斯泥岩是加利福尼亚中北部的一个厚层（约2000米）硅质泥岩单元，似乎与中新世蒙特利组上部有关。该单元暴露在Bolinas-Point Reyes和Santa Cruz地区，在那里它已被沿着圣安德烈亚斯断层系统的运动显著抵消。圣克鲁斯泥岩的年代、地层学和古海洋学尚不清楚。对圣克鲁斯泥岩进行多年研究的主要目标是：(1)利用硅藻生物地层学精确测定圣克鲁斯泥岩的年龄；(2)描述和记录富硅岩和富碳酸盐岩之间的地层旋回；(3)评估圣克鲁斯泥岩内部突出的层理旋回和其他地层变化的时间和古海洋学意义。规划期将有助于初步数据收集和对多年研究计划的有效评价。规划年度的两个主要目标是：(1)进行实地调查工作和取样（硅藻）；(2)评估和综合实地和年龄数据，并撰写具有竞争力的多年研究计划。这项研究最重要的方面是其结果有望反映中新世晚期复杂的气候和海平面变化。这样的结果将增加我们对沉积在古代上升流、高肥力系统下的沉积物的理解。

The Santa Cruz Mudstone is a thick unit (approximately 2000m) of siliceous mudstones in north-central California that appears to be correlative with the upper part of the Miocene Monterey Formation. The unit is exposed in the Bolinas-Point Reyes and Santa Cruz areas where it has been significantly offset by movement along the San Andreas fault system. The age, stratigraphy, and paleoceanography of the Santa Cruz Mudstones are poorly known. The major objectives of a multi-year study on the Santa Cruz Mudstone would be: (1) to precisely date the age of the Santa Cruz Mudstone using diatom biostratigraphy, (2) to describe and document stratigraphic cycles between silica-rich and carbonate-rich rocks, and (3) to assess the timing and paleoceanographic significance of prominent bedding cycles and other stratigraphic variations within the Santa Cruz Mudstone. A planning period will facilitate preliminary data collection and the effective evaluation of a multi-year research plan. Two major objectives during the planning year are: (1) to conduct reconnaissance field work and sampling (for diatoms) and (2) evaluate and synthesize field and age data and write a competitive multi-year research proposal. The most significant aspect of this investigation is the results are expected to reflect complex climate and sea level variations during the late Miocene. Results such as these will increase our understanding of sediments deposited beneath ancient upwelling, high fertility systems.