Late Quaternary Stratigraphic Development of the Ganges-Brahmaputra Margin: Response to Sea Level, Sediment Supply and Rapid Climate Change

Late Quaternary marginal deposits of the Ganges and Brahmaputra Rivers have formed in a tectonically active setting, yielding thick sequences which potentially contain important high-resolution records of terrestrial and marine processes. Recent studies have detailed the delta's stratigraphic development, noting that active tectonics along with high and variable sediment supply (driven in part by climate) control the Ganges-Brahmaputra more significantly than in many other delta systems. In general, fine-grained sediment preservation is favored in areas of active tectonic processes such as folding, block faulting, and subsidence. Coarse-grained deposits dominate the stratigraphy under the control of high-energy fluvial processes, and mixed fine-coarse stratigraphies are found in areas dominantly influenced by eustatic sea-level change. Overprinted upon these spatially varying patterns are temporal patterns related to episodic events (e.g., earthquakes and rivers avulsions) and long-term changes in climate and sediment supply. Future studies of these high-resolution records should reveal much about climate change, landscape evolution and weathering patterns across southern Asia.