中文摘要：

Figuring out whether the sedimentary prove-nance regions of the thick deep-water turbidite systemsdeposited during Middle-Upper Ordovician in SouthQuruqtagh are the intracontinental uplifts or the peripheralorogenic belts is of great significance for us to understand thetectono-sedimentary nature of the northeastern Tarim Basinand basin-range coupling processes in the middle Paleozoic.This paper reports the in situ LA-ICP-MS U-Pb ages and Hfisotope data on detrital zircons from two Middle-UpperOrdovician sandstone samples which were collected fromthe Charchag Formation and the Zatupo Formation in SouthQuruqtagh, respectively. The results show that the studiedtwo samples have extremely similar U-Pb age patterns andHf isotopic compositions, reflecting multiphase tectono-thermal events with age groups of 527-694, 713-870 Ma（peaking at 760 Ma）, 904-1,090, 1,787-2,094 Ma （peakingat 1,975 Ma） and 2,419-2,517 Ma. Combining previousstudies, the presence of age groups of 713-1,090 and1,787-2,094 Ma, respectively, demonstrates that Tarim hadever been a part of Rodinia and Columbia supercontinent.Moreover, 98 % of 713-870 Ma detrital zircons are char-acterized by negative gHf （t） values ranging from -38.07 to-0.61, which are highly consistent with those of Neoprote-rozoic granites from the Quruqtagh area. No Early Paleozoicages （.-470-500 Ma） signifying subduction or collisionevents in Altyn Tagh were detected in the two samples,indicating that the Middle-Late Ordovician sediments inSouth Quruqtagh and northern Mangar depression weremainly derived from intracontinental uplifts, i.e., the NorthQuruqtagh uplift or the Tabei paleo-uplift, rather than theAltyn Tagh. In conjunction with regional sedimentary-tec-tonic background and previous studies, we proposed pre-liminarily that the northeastern Tarim remained as a passivecontinental margin in Late Ordovician and changed into anactive-continental margin in Silurian due to the southwardsubduction of the South-Tianshan Ocean.

英文摘要：

Figuring out whether the sedimentary prove-nance regions of the thick deep-water turbidite systemsdeposited during Middle-Upper Ordovician in SouthQuruqtagh are the intracontinental uplifts or the peripheralorogenic belts is of great significance for us to understand thetectono-sedimentary nature of the northeastern Tarim Basinand basin-range coupling processes in the middle Paleozoic.This paper reports the in situ LA-ICP-MS U-Pb ages and Hfisotope data on detrital zircons from two Middle-UpperOrdovician sandstone samples which were collected fromthe Charchag Formation and the Zatupo Formation in SouthQuruqtagh, respectively. The results show that the studiedtwo samples have extremely similar U-Pb age patterns andHf isotopic compositions, reflecting multiphase tectono-thermal events with age groups of 527-694, 713-870 Ma（peaking at 760 Ma）, 904-1,090, 1,787-2,094 Ma （peakingat 1,975 Ma） and 2,419-2,517 Ma. Combining previousstudies, the presence of age groups of 713-1,090 and1,787-2,094 Ma, respectively, demonstrates that Tarim hadever been a part of Rodinia and Columbia supercontinent.Moreover, 98 % of 713-870 Ma detrital zircons are char-acterized by negative gHf （t） values ranging from -38.07 to-0.61, which are highly consistent with those of Neoprote-rozoic granites from the Quruqtagh area. No Early Paleozoicages （.-470-500 Ma） signifying subduction or collisionevents in Altyn Tagh were detected in the two samples,indicating that the Middle-Late Ordovician sediments inSouth Quruqtagh and northern Mangar depression weremainly derived from intracontinental uplifts, i.e., the NorthQuruqtagh uplift or the Tabei paleo-uplift, rather than theAltyn Tagh. In conjunction with regional sedimentary-tec-tonic background and previous studies, we proposed pre-liminarily that the northeastern Tarim remained as a passivecontinental margin in Late Ordovician and changed into anactive-continental margin in Silurian due to the southwardsubduction of the South-Tianshan Ocean.