Sedimentology and Diagenesis of Phanerozoic Hardgrounds

这项研究将有助于更好地了解显生宙（过去6亿年）硬地层（暴露在海底的海底胶结层）的沉积环境和沉积后的蚀变，并确定硬地层性质与海洋物理和化学性质的时间振荡的关系。通过野外工作和现有收集的大量显生宙硬岩，将使用综合结构-同位素-元素方法系统地研究样品。定量阴极发光光谱法和同步辐射诱导x射线荧光（SRIXE）新技术将增强标准岩相学和微量分析方法。除了提供对硬地沉积学和成岩作用的新认识外，该项目还应：古石灰岩中识别海相钙质胶结物的屈服成分标准；2. 提供有利于水泥沉淀和后续成岩作用的化学条件的新见解；3. 3 .提高对碳酸盐阴极发光的认识；获得关于海洋大气成分和碳酸盐胶结物矿物学的明显时间趋势的新信息。这两种方法的结合将为碳酸盐岩岩石学和沉积学的研究开辟新的途径。

This research will gain a better understanding of the depositional setting and post-depositional alteration of hardgrounds (submarine-cemented layers exposed on the sea floor) during the Phanerozoic (the last 600 million years) and to determine the relationship of hardground properties to temporal oscillations in the physical and chemical nature of the oceans. From a large suite of Phanerozoic hardgrounds through field work and from existing collections, samples will be systematically studied using a integrated textural-isotopic-elemental approach. Standard petrographic and microanalytical methods will be augmented by the new technologies of quantitative cathode luminescence spectrometry and synchrotron radiation induced x-ray fluorescence (SRIXE). In addition to providing a new understanding of hardground sedimentology and diagenesis, the project should: 1. yield compositional criteria by which marine calcitic cements may be recognized in ancient limestones; 2. provide new insight on chemical conditions favoring cement precipitation and subsequent diagenesis; 3. advance the understanding of cathodoluminescence in carbonates, and 4. yield new information on the apparent temporal trends in ocean- atmosphere compositions and carbonate cement mineralogy. The combined methodologies to be employed should open new avenues of research in carbonate petrology and sedimentology.