Metamorphic evolution of gneisses and eclogites along a cross section through the cold and hot eclogite terrane of the Dabie Shan, Central China

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The collision between the Yangtze Craton and the Sino-Korean Craton in the Early Mesozoic resulted after erosion in surficially exposed UHPM rocks indicated, so far, by coesite and/or diamond. The widerspread occurrence of such rocks in the DabieTongbai Mountains and the Jiangsu-Shandong Province (Su-Lu) offers an worldwide almost unique situation to study processes related to deep orogenic roots during continent-continent collision. In a selected area of the Dabie Shan, mainly along a profile in N-S direction, eclogites, ultrabasic and calcsilicate rocks, that are encloses as lenses in gneisses and micaschists, and the country rocks themselves, should be carefully sampled. These rocks are the target of our petrologic research which will mainly include detailed microanalytical investigations with the electron microprobe. Furthermore, it ist intended to use LA-ICP-MS to determine with a minimal site solution trace elements in mineral phases like garnet, phengiet, biotite and/or kyanite. New thermobarometers including that already are being calibrated in Stuttgart, are to be applied to trace elements (e.g. P, Ti, Y, and Zr) of mineral phases. These new methods should result in much more detailed P-T-paths than derived so far. The PT-path derivation that are planned, should be an important contribution to the enlightenment of the geodynamic evolution of the collision orogen and thus will help to understand processes at deep orogenic roots.