We investigated the spatiotemporal distribution of1 37Cs radioactivity in surface sediment of Qinghai Lake,and developed the spatial pattern of sedimentation rate.The1 37Cs inventory is higher near the estuary/bank ar...We investigated the spatiotemporal distribution of1 37Cs radioactivity in surface sediment of Qinghai Lake,and developed the spatial pattern of sedimentation rate.The1 37Cs inventory is higher near the estuary/bank area,but lower at the central lake.On the other hand,the average1 37Cs activity is lower near the estuary/bank area,but higher at the central lake.The mass accumulation rate(MAR) and the fluxes and contents of the terrestrial detritus(e.g.SiO2,Fe2O3,and Ti) are higher near the estuary/bank area,but lower at the central lake.The chemical/biogenic deposits(e.g.the autogenic carbonates) take up higher fractions at the central lake.These suggest that the spatial pattern of recent sedimentation rate is dominated by the deposition of terrestrial detritus.The average MAR(0.0337 g cm-2a-1) was estimated based on those of different cores of Qinghai Lake and was verified by a Ca mass-balance method.The fluxes of total lake sediments,terrestrial detritus,and direct atmospheric deposits were also estimated.展开更多
基金supported by the National Key Technology R&D Program (Grant No.2007 BAC30B01)West Light Foundation of the Chinese Academy of Sciences(Grant No.2007ZD01)
文摘We investigated the spatiotemporal distribution of1 37Cs radioactivity in surface sediment of Qinghai Lake,and developed the spatial pattern of sedimentation rate.The1 37Cs inventory is higher near the estuary/bank area,but lower at the central lake.On the other hand,the average1 37Cs activity is lower near the estuary/bank area,but higher at the central lake.The mass accumulation rate(MAR) and the fluxes and contents of the terrestrial detritus(e.g.SiO2,Fe2O3,and Ti) are higher near the estuary/bank area,but lower at the central lake.The chemical/biogenic deposits(e.g.the autogenic carbonates) take up higher fractions at the central lake.These suggest that the spatial pattern of recent sedimentation rate is dominated by the deposition of terrestrial detritus.The average MAR(0.0337 g cm-2a-1) was estimated based on those of different cores of Qinghai Lake and was verified by a Ca mass-balance method.The fluxes of total lake sediments,terrestrial detritus,and direct atmospheric deposits were also estimated.
