The Late Neogene ~(87)Sr/~(86)Sr Record of Lowland Himalayan Rivers

摘要

Fossil shells and paleosol carbonate from ancestral Himalayan river deposits provide a ~(87)Sr/~(86)Sr record of lowland Himalayan river water during the late Neogene. Reconstructed ~(87)Sr/~(86)Sr river values increased sharply in the late Miocene, probably marking the beginning of exhumation of high-~(87)Sr/~(86)Sr metalimestones, more in the central than in the western Himalayas. These results imply that the marine ~(87)Sr/~(86)Sr record may not be a proxy for silicate weathering or consumption of atmospheric CO_2 resulting from that weathering.