The principle,application,and prospect of using the uranium comminution age to indicate the catchment erosion depth  

作　　者：Hongmin XU Chao LI Zhifei DUAN Yulong GUO Shouye YANG 

机构地区：[1]State Key Laboratory of Marine Geology,Tongji University,Shanghai 200092,China [2]School of Ocean and Earth Sciences,Tongji University,Shanghai 200092,China

出　　处：《Science China Earth Sciences》2023年第7期1439-1449,共11页中国科学（地球科学英文版）

基　　金：supported by the National Key Research and Development Program of China (Grant No.2022YFF0800504);the National Natural Science Foundation of China (Grant Nos.41991324,42273057,42076063);the Natural Science Foundation of Shanghai (Grant Nos.20ZR1460400,21590712700);State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,CAS (Grant No.SKLLQG2222)。

摘　　要：Catchment erosion not only shapes various landforms of the earth’s surface but also affects the rates of chemical weathering and CO_(2) absorption by controlling the exposure of rock fragments,and thus acts as a regulator of the global climate.Therefore,studying the occurrence and controlling factors of catchment erosion can improve our understanding of topographic evolution and long-term climate change.This paper introduces the“comminution age”method based on (^(234)U/^(238)U) of sediment detrital components and its applications to indicate the catchment erosion depth,which is widely applied to different depositional environments.In tectonically stable regions,where there is shallow erosion,the sediment output from the catchment is usually accompanied by a low (^(234)U/^(238)U).On the other hand,where there is deep erosion,the (^(234)U/^(238)U) of the downstream sediments is usually high.In tectonically active regions,deep erosion is common,and the sediment erosion process is subject to rapid material transport,such as landslide-induced sediment displacement.Since the sediment exposure history is short,the (^(234)U/^(238)U) of the detrital components is close to 1,thus reaching“secular equilibrium”.The comminution age method is promising in terms of tracing catchment erosion depths at the orbital scale.Furthermore,this method is also sensitive to the erosion changes caused by rapid climate changes and human activities.

关 键 词：Catchment scale Erosion depth Comminution age (^(234)U/^(238)U) 

分 类 号：P512.2[天文地球—地质学] P53