An integrated north–south paleo-Dadu-Anning River: New insights from bulk major and trace element analyses of the Xigeda Formation

作     者：Yong Zheng Hai-bing Li Jia-wei Pan Ping Wang Ya Lai Zheng Gong Yong Zheng;Hai-bing Li;Jia-wei Pan;Ping Wang;Ya Lai;Zheng Gong

作者机构：Key Laboratory of Deep-Earth DynamicsInstitute of GeologyChinese Academy of Geological SciencesChina Geological SurveyMinistry of Natural ResourcesBeijing 100037China Jiangsu Donghai Continental Deep Hole Crustal Activity National Observaion and Research StationLianyungang 222300China Southern Marine Science and Engineering Guangdong LaboratoryGuangzhou 511458China Geophysical Exploration CenterChina Earthquake AdministrationZhengzhou 450002China Institute of GeophysicsChina Earthquake AdministrationBeijing 100081China 

出 版 物：《China Geology》 (中国地质（英文）)

年 卷 期：2024年第7卷第1期

页      面：91-103页

核心收录：

学科分类：070904[理学-构造地质学] 070903[理学-古生物学与地层学(含：古人类学)] 0709[理学-地质学] 07[理学] 

基　　金：financially supported by the Natural Science Foundation of China(41941016,42072240,41830217) Ministry of Science and Technology of China(2019QZKK0901,2021FY100101) Key Special Project for Introduced Talents Team of the Southern Marine Science and Engineering Guangdong Laboratory(GML2019ZD0201) China Geological Survey(DD20221630) Special Fund of the Institute of Geophysics,China Earthquake Administration(DQJB20B21) 

主　　题：Dadu River Anninghe fault River diversion Xigeda Formation Tectonic uplift Provenance Songpan-Ganzi flysch Ancient lake Xianshuihe-Xiaojiang fault system Tibetan Plateau 

摘      要：The Xianshuihe-Anninghe fault extends SE–S and constitutes the southeastern margin of the Tibetan ***,the Dadu River which is associated with the fault does not flow following the path,but makes a 90ºturn within a distance of 1 km at Shimian,heading east,and joins the Yangtze River,finally flowing into the East China *** to the abrupt turn,a low and wide pass near the Daqiao reservoir at Mianning separates the N–S course of the Dadu River from the headwater of the Anning River which then flows south into the Yunnan Province along the Anninghe ***,many previous studies assumed southward flow of the paleo-Dadu River from the Shimian to the Anning ***,evidences for the capture of the integrated N–S paleo-Dadu-Anning River,its timing,and causes are still *** study explored the paleo-drainage pattern of the Dadu and Anning Rivers based on bulk mineral and geochemical analyses of the large quantities of fluvial/lacustrine sediments along the trunk of the Dadu and Anning *** with sands in the modern Dadu River,the Xigeda sediments also exhibit a granitoid affinity with the bulk major mineral compositions of quartz(50%),anorthite(about 10%),orthoclase(about 5%),muscovite(about 5%),and clinochlore(about 4%).Correspondingly,bulk major elements show high SiO_(2),with all samples60%,and some of them70%,low TiO_(2)(≤0.75%),P_(2)O_(5)(≤0.55%),FeO*(≤5%),and relatively high CaO(1.02%–8.51%),Na_(2)O(1.60%–2.52%),and K_(2)O(2.17%–2.71%),with a uniform REE ***,synthesizing all these results indicate that these lacustrine sediments have similar material sources,which are mainly derived from its course in the Songpan-Ganzi flysch block,implying that the paleo-Dadu originally flowed southward into the Anning River and provided materials to the Xigeda ancient *** rearrangement of the paleo-Dadu River appears to be closely related to the locally focused uplift driven by strong activities of the Xians