Exploring the tectonostratigraphy of the Pakistan Himalaya with new detrital zircon geochronology and neodymium isotope data from the Kaghan Valley

查看全文 作　　者：W.Joel [1]Schiffer;Delores [1]M.Robinson;Shah [2]Faisal;Harold [1]H.Stowell 机构地区：[1]Department of Geological Sciences and Center for Sedimentary Basin Studies,University of Alabama,PO Box 870338,Tuscaloosa,AL 35487,USA;[2]National Centre of Excellence in Geology,University of Peshawar,Peshawar 25130,Pakistan 出　　处：《Geoscience Frontiers》索引2023年第14卷第6期,共16页 基　　金：This work was made possible by funding support from National Academy of Sciences Prime Cooperative Agreement No.AID-391-A-17-00001 to Dr.Robinson;Pakistan-U.S.Science and Technology Cooperation Program Phase-VII No.HEC/R&D/PAK-US/2017/360 to Dr.Faisal;Additional funding was provided by Graduate Student Research Grant 13308-21 from the Geological Society of America to Joel Schiffer;Logistical support in the field was provided by faculty and students at the National Centre of Excellence in Geology,University of Peshawar,Pakistan.Mineral separations,sample preparation,and analytical services were carried out with the help of GeoSep Services,the Arizona LaserChron Center,and students at the RadIs Laboratory,University of Alabama. 摘　　要：In the central Himalaya,the Greater and Lesser Himalayan tectonostratigraphic zones can be distinguished from each other by combining detrital zircon U-Pb ages and whole-rock Nd isotopic data.In the Hazara-Kashmir syntaxis of northern Pakistan,rock units in the Kaghan valley have been variously assigned to the Tethyan,Greater,and Lesser Himalayan zones.To determine which tectonostratigraphic zones are represented,we sampled across the Batal thrust in the northern Kaghan valley because this structure is identified in some research as the Main Central thrust.Samples from the footwall yield Paleo-to Mesoproterozoic maximum depositional ages(-1.8-1.1 Ga)and an averageεNd(0)value of-14.3.Samples from the hanging wall yield Neoproterozoic maximum depositional ages(~1000-600 Ma)andεNd(0)values of-17.3.The contrasting detrital zircon ages show that the Batal thrust in the Kaghan valley is a major structural division.However,these data lack the characteristic detrital zircon age spectra andεNd(0)values of Greater and Lesser Himalayan rocks north and south of the Main Central thrust in the central Himalaya,respectively.Therefore,either the Batal thrust is not the Main Central thrust,or the Main Central thrust in the Kaghan valley cuts a different structural level and carries rock units not seen outside the Hazara-Kashmir syntaxis. 关 键 词：Pakistan HIMALAYA Tectonostratigraphy Main Central thrust Detrital zircon geochronology Neodymium isotopes