Exploring the archive data of low grade - high pressure metamorphic sedimentary successions

尽管有蓝片岩相高压变质作用，但西安纳托利亚安纳托利德-陶里德带的变质沉积岩具有广泛分布的原生沉积结构。与这一提议相关的岩石类型包括新特提斯群岛下白垩统远洋序列中以前未描述的蒸发序列。这些岩石暴露在大片区域，并在时间上与大西洋的阿普提亚蒸发岩相关联。初步工作表明，在早期成岩作用中，具有重要体积重要性的原生亚硒酸盐晶体(长达1.5m)转化为文石。与俯冲有关的深埋藏之后是折返，导致文石向方解石转化。在这些过程中，宏观和微观的初级织构和结构保持不变。岩石学研究发现，在这些岩石的选定区域中，原始结构保存得非常完好。我们建议使用矿物学工具(EMPA、拉曼光谱、阴极发光)、地球化学(LA-ICPMS)和同位素地球化学(Delta18O、Delta13C、Delta26 Mg和87Sr/86Sr)来研究多重假象现象。这些研究的目的是加强对早期成岩过程和变质反应的了解，并对元素通量进行量化。本文提出的研究将极大地提高对低品位高压变质沉积岩中的地球化学通量和热力学过程的认识，从而提高对这些档案岩的认识。

Despite blueschist facies high pressure (HP) metamorphism, metasedimentary rocks of the Anatolide-Tauride belt in western Anatolia exhibit widely distributed primary sedimentary texture. The rock types relevant for this proposal comprise previously undescribed evaporitic sequences in Lower Cretaceous pelagic successions of the Neotethys. The rocks are exposed over large areas and correlate in time to Aptian evaporites in the Atlantic ocean. Preliminary work showed that volumetrically important abundances of primary selenite crystals (up to 1.5 m crystal length) were transformed to aragonite during early diagenesis. Subduction-related deep burial was followed by exhumation, which led to the transformation from aragonite to calcite. Along with these processes, macro- and microscopic primary textures and structures remained unaltered. Petrographic investigations revealed exceptionally well-preserved primary textures in selected domains of these rocks. We propose to investigatephenomena of multiple pseudomorphism using mineralogical tools (EMPA, Raman spectrometry, cathodoluminescence), geochemistry (LA-ICP-MS) and isotope geochemistry of delta18O, delta13C, delta26Mg and 87Sr/86Sr isotopes. The aim of these investigations is to enhance the understanding of early diagenetic processes and metamorphic reactions as well as to quantify element fluxes. The research proposed here will potentially lead to a significantly increased understanding of geochemical fluxes and thermodynamic processes in low grade HP metasedimentary rocks leading to an improved understanding of these archive rocks.