PROJECT DETAILS ONLY. Mountain belts disrupt atmospheric circulation patterns and profoundly influence climate. Understanding long-term climate change thus requires good definition of timing and growth rate of major mountain belts, but is complicated by high erosion rates which remove much of the early record of mountain formation. Sophisticated geodynamic and climate-atmosphere models describe the evolution and influences of the Himalayan-Tibet orogen. Many geodynamic models predict palaeogene crustal thickening with little or no early exhumation and erosion. Such models need testing. Decades of geological, geophysical and geochemical investigations centred on the continental rock record have failed to produce data sets suitable for testing fully such models because information about the early orogen evolution is missing. Our alternative strategy looks at marine sediments formed from material eroded in the early history of the mountain belt and preserved in the Andaman Islands, Sylhet Trough, Bangladesh and Iranian Makran. These sediments contain a record of their origin and early history in the Himalayas-Tibet which can be recovered using a combination of geochemical and thermochronological methods. Results from this project will provide the groundwork for major international collaborative projects to drill sediments eroded off the Himalayas and deposited offshore in the Indus and Bengal submarine fans.
