The suturing of continental fragments following the subduction of intervening oceanic lithosphere is a fundamental process in lithospheric dynamics and the shaping and growth of Earth?s continents. However, our understanding of this fundamental process remains limited. Ancient sutures manifest themselves in regional structural, sedimentary, and petrologic patterns across thousands of kilometers, and record evidence of past plate dynamics. The suturing process itself results in drastic changes in plate dynamics, creates Earth?s largest mountain belts, and changes global climate dynamics by closing ocean basins and raising high topography. In terms of a fundamental and global tectonic process, suturing is on par with oceanic subduction and mid-ocean ridge formation, yet little more can be found in Earth-science textbooks than its definition and passing reference to the India?Asia collision. The primary aims of this project are to understand the geodynamic processes before, during, and after suturing, and how these processes impact continental physiography and are expressed in the geological record. To achieve this goal, the PIs propose to study the India?Asia collision zone (IACZ) in southern Tibet and the northern Himalaya. Techniques to be employed include structural geology, stratigraphy, geochronology, thermochronology, stable and radiogenic isotope geochemistry, igneous and metamorphic petrology, paleomagnetism, and numerical geodynamical modeling of the associated processes.
