In situ cosmogenic ^(10)Be, ^(26)Al, and ^(21)Ne dating in sediments from the Guizhou Plateau, southwest China  

作　　者：Ye YANG Yu LIU Yan MA Sheng XU Cong-Qiang LIU Shi-Jie WANG Finlay M.STUART Derek FABEL 

机构地区：[1]Institute of Surface-Earth System Science,School of Earth System Science,Tianjin University,Tianjin 300072,China [2]Scottish Universities Environmental Research Centre,East Kilbride G750QF,UK [3]State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China [4]State Key Laboratory of Earthquake Dynamics,Institute of Geology,China Earthquake Administration,Beijing 100029,China

出　　处：《Science China Earth Sciences》2021年第8期1305-1317,共13页中国科学（地球科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.41930642)。

摘　　要：Landscape evolution is modulated by the regional tectonic uplift,climate change,and river dynamics.However,how to distinguish these mechanisms through the research of surface exhumation and fluvial incision remains controversial.In this study,cosmogenic ^(10)Be,^(26)Al,and ^(21)Ne concentrations in quartz from cave deposits,modern river sediments,and bedrocks were measured to constrain the applicability of cosmogenic ^(21)Ne and discuss Quaternary landscape evolution history in the Guizhou Plateau,southeast China.Using the ^(26)Al-^(10)Be and ^(21)Ne-^(10)Be pairs to distinguish the cosmogenic ^(21)Ne concentration from the excess ^(21)Ne,we found that the nucleogenic ^(21)Ne produced by the U and Th decay in quartz is significant in the samples although there is the possibility of inherited cosmogenic ^(21)Ne.Combining with previous studies,we suggest that the precise approach for applying the cosmogenic ^(21)Ne could be reached by(1)estimating the contribution from nucleogenic ^(21)Ne,(2)avoiding samples with complex burial histories to exclude inherited cosmogenic ^(21)Ne,and(3)combining the ^(10)Be-^(26)Al-^(21)Ne nuclides method for the Quaternary samples.In addition,both pre-burial basin denudation rates and burial ages derived from the ^(26)Al-^(10)Be pair were used to determine the different timescale surface denudation rate and fluvial incision rate in relation to previous work.The consistency of the different timescales pre-burial basin denudation rate,^(36)Cl surface denudation rate,and modern basin denudation rate indicates that the landscape-scale surface denudation has been likely stabilized since the Quaternary in the Guizhou Plateau area.The slightly higher river incision rates than the local surface denudation rate show that the river dynamics may not have reached a steady-state due to the regional tectonic uplift in the Guizhou Plateau.

关 键 词：Cosmogenic^(10)Be-^(26)Al-^(21)Ne Burial dating Incision rate Landscape evolution Guizhou Plateau 

分 类 号：P53[天文地球—古生物学与地层学]