Executive Summary : | The Himalayan mountains, a climate-tectonically active regions of the world, has a strong influence on geochemical budget, sediment and carbon sequestration. Therefore, it is important to understand the role of climate and tectonics on the weathering, erosional pattern in the mountains, and sedimentation in the flood plain and deltaic region. The motivation for this study comes from our ongoing geochemical research on outcrop sedimentary sequences from the central Ganga flood plain. The chemical weathering and sediment provenance record from the central Ganga flood plain suggests that both climate and basin tectonics play a major role in the southern Ganga Plain sedimentation. The geochemical record revealed that the chemical weathering and erosion of source rocks are predominantly controlled by the monsoon climate. However, prominent shift in sediment provenance from peninsular mafic dominated sediments to Himalayan felsic sediments at around 40-45 ka is attributed to intra-basin tectonic activity (Yadav et al., 2023; shukla et al., 2012). The mafic sediments are preferentially transported in suspension leaving the coarser flood plain sediments felsic biased (Garçon and Chauvel, 2014; Yadav et al., 2023). The Bengal Fan sediments carry important information pertaining to geological history of the continental rocks in the hinterland and the environmental conditions of their formation (Ahmad et al., 2005; Colin et al., 1999). The study of clastic sedimentary and geochemical characteristics would help to pinpoint the sediment provenance, which in-turn, could provide clues about the possible location of enhanced monsoon precipitation, and erosional and tectonic activity in the continental region. Further, there are no sedimentary record available in the literature from Bay of Bengal beyond last glacial maxima (LGM), especially from northern Bay of Bengal which documents the role of tectonic activity in the Bay of Bengal sedimentation. The available studies are focused on the western margin of Bay of Bengal, located in the central and southern part of Bay of Bengal, where east flowing rivers of Peninsular India brings the mafic sediments from Deccan province. Therefore, in this project, we study the late Quaternary sedimentary record from Bay of Bengal to characterize the sediment erosion, provenance and climate-tectonic history of Ganga -Brahmaputra (G-B) Basin by studying the sediment cores from northwestern Bay of Bengal (Core VM29, 18) and northeastern Bay of Bengal (Core ANTP, 166P). The sediments will be studied for sediment texture, clay mineralogy, elemental geochemistry (major, trace and rare earth elements) and radiogenic isotopes (87sr or 86sr and εNd; in both clay fraction and bulk sediments) to infer the weathering in the source region and provenance characteristics. Further, the Bay of Bengal dataset would be further compared with the continental records of hinterland to decipher the role of climate and tectonics in source-sink processes. |