In situ cosmogenic ^(10)Be in quartz from loess deposited in the last 2,000,000 a is considered to have been derived mainly from initial ^(10)Be in source regions and it bears abundant information about changes in ero...In situ cosmogenic ^(10)Be in quartz from loess deposited in the last 2,000,000 a is considered to have been derived mainly from initial ^(10)Be in source regions and it bears abundant information about changes in erosion rates of source regions. As [have been estimated, the concentrations of 'in situ cosmogenic ^(10)Be' in quartz from samples GL47(L1) andGL83 (L2) collected from the Luochuan loess section are 5×10~5 atom/g and 2.2×10~6 atom/g, respectively. As calculated on the basis of the above estimates, the erosion rates of the source regions are: εBeL1=1.5×10^(-3) cm/a for the L1 period (10,000—90,000 a) and εBeL2=3.8×10^(-4) cm/a for the L2 period (130,000—190,000 a). Studies of 'in situ cosmogeuic ^(10)Be' in quartz from loess at deeper levels are expected to be applied to ^(10)Be dating of loess strata.展开更多
基金This work was financially supported both by the Swiss National Science Foundation and by the National Natural Science Foundation of China
文摘In situ cosmogenic ^(10)Be in quartz from loess deposited in the last 2,000,000 a is considered to have been derived mainly from initial ^(10)Be in source regions and it bears abundant information about changes in erosion rates of source regions. As [have been estimated, the concentrations of 'in situ cosmogenic ^(10)Be' in quartz from samples GL47(L1) andGL83 (L2) collected from the Luochuan loess section are 5×10~5 atom/g and 2.2×10~6 atom/g, respectively. As calculated on the basis of the above estimates, the erosion rates of the source regions are: εBeL1=1.5×10^(-3) cm/a for the L1 period (10,000—90,000 a) and εBeL2=3.8×10^(-4) cm/a for the L2 period (130,000—190,000 a). Studies of 'in situ cosmogeuic ^(10)Be' in quartz from loess at deeper levels are expected to be applied to ^(10)Be dating of loess strata.
