Chemical weathering in the river basins of the Himalaya, India

Rivers transport weathered materials from land to the ocean. The chemistry of river waters is dictated by supply of various elements from both natural and anthropogenic sources. Among the natural sources, chemical weathering of the drainage basin is the dominant component, a process which consumes atmospheric CO2. On timescales of millions of years, atmospheric CO2 balance and. hence global climate is influenced by chemical weathering process, silicate weathering in particular. The suggestion that silicate weathering in the Himalaya may be a driver of global cooling during the Cenezoic(1-3) has prompted many studies on rivers draining the Himalaya, especially the source waters of the Ganga-Brahmaputra. This article reviews some of these studies and presents the current thinking on this topic.