CLIMATE-TECTONIC INTERACTIONS IN THE ARABIAN SEA

The Asian monsoon is one of the most intense climatic phenomena on Earth. The Arabian Sea monsoon is part of Asian monsoon, adjoining the Indian continental margin, offers a unique opportunity to investigate tectonic–climatic interactions and the net impact of these processes on weathering and erosion of the western Himalaya. During International Ocean Discovery Program (IODP) Expedition 355, two sites (U1456 and U1457) were drilled in Laxmi Basin in the eastern Arabian Sea in May 2015. By using methods of TNd and Sr isotopes, U-Pb single grain zircon dating, clay mineralogy, bulk sediment geochemistry, and apatite fission track on the core samples from these two sites, we will investigate how erosion in the Western Himalaya may be linked to changes in monsoon intensity since the late Miocene. Development of high topography in Asia and changes in monsoon strength represent the world type example of how the solid Earth and atmosphere might influence each other over timescales of greater than 1 Ma. We are reconstructing the changing patterns and rates of erosion in the mountains have changed since around 11 million years ago. We will establish if there are links between the structural evolution of the mountains and changing surface processes. We further aim to link erosion and weathering with environmental conditions reconstructed by palynology and biomarker work.