Late Quaternary tectonic uplift and Yellow River evolution create high arsenic aquifers in the Hetao Basin,China  

作　　者：Haoyue Zhang Xujiao Zhang Peisheng Ye Chenglu Li Junlei Li Xiaoning Yuan Xiangge Zhang Huaming Guo Pat J.-F.Yeh 

机构地区：[1]Yanchi Research Station,School of Soil and Water Conservation,Beijing Forestry University,Beijing 100083,China [2]School of Earth Sciences and Resources,China University of Geosciences,Beijing 100083,China [3]Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China [4]School of Water Resources and Environment,China University of Geosciences,Beijing 100083,China [5]Department of Civil Engineering,Monash University,Malaysia Campus,Malaysia

出　　处：《Geoscience Frontiers》2024年第6期167-175,共9页地学前缘（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.42301094,41972192,and 41825017)。

摘　　要：High arsenic(As)groundwater is a global problem primarily originating from As-enriched sediments.The provenance(source)and release mechanisms(sinks)of high As sediment have been identified,but the source-sink transfer is poorly understood,especially the influence of geological and surface processes.In this study,we explore the roles of tectonic movement and Yellow River evolution in provenance formation processes and evaluate the combined effects of provenance and sediment age on the As content of aquifer sediments in the northern Hetao Basin of Inner Mongolia.Based on optically stimulated luminescence(OSL)and 14C dating and detrital zircon U-Pb,As content,and lithological analyses of a 400 m core,we reconstructed As changes over the last 160 ka.Our results show clay deposited in a paleo-lake during the Gonghe movement period in the late Pleistocene(∼100 ka B.P.)is enriched in As(31.8μg/g)due to significant provenance contributions of the As-bearing Langshan Group under tectonic uplift and mountain erosion.In contrast,clay deposited in the middle Pleistocene(∼160 ka B.P.)has lower As content(7.3μg/g)due to the Yellow River as the primary provenance.Accordingly,the provenance of basin As forced by tectonic uplift and Yellow River evolution determines the background As of aquifer sediments.After deposition,sediment As content decays over time,with higher decay rates in coarse-grained sands than fine-grained.Overall,both provenance formation and sediment age,representing initial and dynamic states of solid phase As,jointly determine the As content of aquifer sediments.More solid phase As provided by younger sediments from the proximal orogenic provenance and reducing conditions due to frequent river-lake transitions,jointly lead to higher As concentrations in shallow groundwater.The study highlights the potential for using a combined analysis of the tectonic movement-surface processes-environment system to improve understanding of geogenic high As groundwater over global large sedimentary basins in the proximi

关 键 词：High arsenic groundwater PROVENANCE Tectonic uplift Yellow River evolution Surface processes Hetao Basin 

分 类 号：P542[天文地球—构造地质学]