Diagenetic Record of Transgressive Regressive Events

研究者建议研究海侵-退积层序中的成岩改造作用。这项系统的研究将包括三个主要部分：a)波多黎各北部第三系海侵-退积层序的详细地球化学和岩石学特征；B)利用经验数据约束模型对海侵-退变成岩环境进行地球化学模拟；c)对北美中部大陆的一个古生代序列进行详细的地球化学和岩石学研究，以检验这些模型的适用性和第三纪古生代类似物的实用性。岩石学表征将包括在双眼显微镜和偏光显微镜下对抛光板和薄片进行常规岩石学检查，使用阴极发光和荧光显微镜对抛光薄板和薄片进行检查，以及通过扫描电子显微镜进行检查。选定组分的地球化学表征将包括微量、微量和超微量元素测定、碳和氧稳定同位素组成以及87Sr/86Sr测定。建模将包括流体化学的地球化学建模和系统的矿物稳定性，以评估系统的热力学限制，以及成岩-海平面振荡模型，以评估地质记录中可能出现的各种情况。

The investigator proposes to study diagenetic modifications in transgressive-regressive depositional sequences. This systematic study will include three major components: a) detailed geochemical and petrographic characterization of transgressive-regressive Tertiary sequences of Northern Puerto Rico; b) geochemical modelling of transgressive-regressive diagenetic settings using the empirical data to constrain models; and c) detailed geochemical and petrographic study of a Paleozoic sequence in the central North American midcontinent to test applicability of such models and usefulness of Tertiary analogues for the Paleozoic. Petrographic characterization will include conventional petrographic examination of polished slabs and thin sections under binocular microscopes and polarizing microscopes, examination of polished thin slabs and thin sections using cathodoluminescence and fluorescence microscopy, and examination by scanning electron microscopy. The geochemical characterization of selected componenets will include minor, trace and ultra-trace element determinations, carbon and oxygen stable isotope compositions and 87Sr/86Sr determinations. Modelling will include geochemical modelling of fluid chemistry and mineral stability of the systems to assess the thermodynamic limitations of the system, and diagenesis-sea level oscillation models to evaluate a broad range of scenarios that could be present in the gologic record.