NSFGEO-NERC: Impact of the Plio-Pleistocene Transition on Provenance and Sediment Routing from the Himalaya to the Deep-Sea Bengal Fan

The Himalayas represent the largest mountain chain on Earth, and reside mostly in Nepal, India, Pakistan and China. The Himalayas began rising many millions of years ago when India collided with Asia, which changed Earth's climate, altered ocean circulation and chemistry, and impacted the course of biological evolution. Erosion of the Himalayas resulted in deposition of the largest pile of sediment on the planet in the Bay of Bengal, the deep-sea Bengal Fan. Within this sediment record lies the history of the Himalayas - the now eroded Mt. Everests of the past, buried under sediment of the continental shelf and the deepest parts of the Indian Ocean. In 2015, a multi-national expedition on the Joides Resolution, a specially designed drill ship, recovered ~1.5 miles of drill core that contains this record. New research will use sediment from these cores to trace the history of Himalayan erosion and how two of the world's largest rivers, the Ganges and Brahmaputra, delivered this sediment to the Bay of Bengal over the last 3-5 million years. Giant mountain ranges like the Himalayas are a rarity through geologic history, but without the Himalayas there are no drenching Asian monsoons, no fertile floodplains or aquifers, no ancient Indus Civilization, and no Mt. Everests in that part of the world. The results of this research will therefore tell us about climate change, landscape evolution, and how one of the world's most densely populated areas came to be as we see it today. Understanding the past in this way can help us better understand the future for the 10% of the world's population that lives under the influence of this incredible geographic feature.