Noble gases in ultra-high-pressure eclogites and peridotites of the CCSD core

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The noble gases He, Ne, Ar, Kr, Xe (altogether 23 isotopes) are important tracers for the evolution and history of mantle-derived rocks, and fluid-rock interaction with crustal or atmosphere-derived fluids. Isotope signatures of various mantle, crustal and atmospheric components, and frequently observed pronounced elemental fractionation of these components offer an enormous sensitivity to distinguish a variety of processes. While oceanic basalt glasses and mantle xenoliths from both oceanic and various subcontinental settings are characterized to increasingly better degrees, this study aims to obtain the first noble gas isotope data in UHP eclogites and peridotites, and a complete characterization of UHP rocks from the core of the Chinese Continental Scientific Drilling Program (Donghai). Isotopic compositions will allow to identify possible mantle (deep/shallow), crustal and atmosphere-derived components. The history of these components and their carrier phases and host rocks can be further constrained by fractionation processes reflected in element ratios. Correlations with oxygen isotopes and other geochemical/petrographic parameters will be achieved by cross-collaboration with other groups investigating the respective CCSD core sections. In particular, this study has the potential to yield insight into crust-mantle interaction and mantle-behaviour in convergent plate-boundaries, and fluid action within convergent plate boundaries.