9417958 Liou This project will study the emplacement mechanisms of ultrahigh-pressure rocks that have been recently discovered in the Dabie Mountains in China. These eclogitic rocks contain minerals that indicate extremely deep burial, and the processes by which they were uplifted to the surface are unknown. The project will attempt to identify the strain history and deformation rates along major faults that bound the eclogitic rocks. Thermobarometry, metamorphic phase relations, and geochronology of the rocks within and on either side of the deformation zones will be used to assess the temperatures and pressures during deformation and the magnitude and timing of vertical displacement. This project will be the first study of the tectonic history of these ultrahigh-pressure rocks. The results will provide an understanding of the physical processes operative in the deepest levels of collisional orogens, and will illuminate the linkage among deep and shallow levels to tectonism.