INTEGRATED PROVENANCE ANALYSIS OF A COMPLEX OROGENIC TERRANE: MESOZOIC UPLIFT OF THE BOGDA SHAN AND INCEPTION OF THE TURPAN-HAMI BASIN, NW CHINA

摘要: We employ petrographic and advanced geochemical tech- niques to better document the evolution of Turpan-Hami basin based on unique geologic histories arc terranes that served as potential sources deposits. First, a provenance study Permian through Cretaceous sandstone reveals temporal spatial changes in dominant source ter- ranes provided detritus basin. Volcanic-lithic-rich Upper (mean Qm 19F18Lt63 ;Q p 7Lvm89Lsm4 m 48P39K13) followed by more quartzose compositions Triassic 41F19Lt40 20Lvm75Lsm5 68P21K11) indicate progressive un- roofing extinct northern central Tian Shan south Turpan-Hami. A sharp change sedimentary-lithic-rich Lower Jurassic 47F16Lt37 16Lvm42Lsm42; 75P12K13) overlain return volcanic-lithic-rich Middle Ju- rassic 39F21Lt40 14Lvm51Lsm35 65P21K14) points initial uplift unroofing largely andesitic Bogda north, which first shed its sedimentary cover it emerged become partition between southern Jung- gar basins. Second, geochronological, trace-element, Sm-Nd isotopic varia- tions among granitoids late Paleozoic orogenic belt provide further test Mesozoic Shan. On basis previous models crustal throughout South, Central, North Shan, East West terranes, we infer isotopically enriched granitic cobbles (av- erage eNdi 5 20.50, n 6) contained deposits north-central were derived from continen- tal Central terrane, Turpan-Hami, not oceanic Junggar north therefore ancestral had been uplifted Early Triassic, prior this time, unified Junggar-Turpan-Hami existed during Late deposition extensive lacustrine