Material Composition of the Newly Discovered Zongzhuo Formation Sedimentary Mélange in the Dingri Area,Southern Tibet,and its Constraints on the Basin Controlling Dingri-Gamba Fault  

作　　者：YAN Songtao DING Ailing DAI Xuejian LI Hu LIU Tao ZHU Lidong WU Qingsong 

机构地区：[1]Civil-Military Integration Center of China Geological Survey,China Geological Survey,Chengdu 610036,China [2]School of Software Engineering,Chengdu University of Information Technology,Chengdu 610225,China [3]College of Earth Science,Chengdu University of Technology,Chengdu 610059,China [4]Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,China

出　　处：《Acta Geologica Sinica(English Edition)》2024年第5期1171-1186,共16页地质学报（英文版）

基　　金：supported by the Geological Survey Project of the China Geological Survey(Grant No.DD20211547);the Basic Survey Project of the Command Center of Natural Resources Comprehensive Survey(Grant No.ZD20220508)。

摘　　要：The study of sedimentary mélanges holds pivotal importance in understanding orogenic processes and unveiling geodynamic mechanisms.In this study,we present findings on zircon U-Pb isotopes and whole-rock elemental data concerning the recently uncovered Zongzhuo Formation sedimentary mélanges within the Dingri area.Field observations reveal the predominant composition of the Zongzhuo Formation,characterized by a matrix of sandstone-mudstone mixed with sand-conglomerates within native blocks exhibiting soft sediment deformation.Moreover,exotic blocks originating from littoral-neritic seas display evidence of landslide deformation.Our study identifies the depositional environment of the Zongzhuo Formation in Dingri as a slope turbidite fan,with its provenance traced back to the passive continental margin.Notably,this contrasts with the Zongzhuo Formation found in the Jiangzi-Langkazi area.Based on existing data,we conclude that the Zongzhuo Formation in the Dingri area was influenced by the Dingri-Gamba fault and emerged within a fault basin of the passive continental margin due to Neo-Tethys oceanic subduction during the Late Cretaceous period.Its provenance can be attributed to the littoral-neritic sea of the northern Tethys Himalaya region.This study holds significant implications for understanding the tectonic evolution of Tethys Himalaya and for reevaluating the activity of the Dingri-Gamba fault,as it controls the active deposition of the Zongzhuo Formation.

关 键 词：sedimentary mélange provenance analysis Zongzhuo Formation Dingri-Gamba fault Tethys Himalaya 

分 类 号：P587[天文地球—岩石学] P542[天文地球—地质学]