新疆大地构造演化基本特征

BASIC CHARACTERISTICSOF GEOTECTONIC EVOLUTION OF XINJIANG

新疆大地构造发展演化经历了 :1.古陆核及原始古陆的形成与解体 ;2 .元古宙末期( 80 0～ 90 0 Ma)联合古陆的形成 ;3.震旦—奥陶纪联合古陆裂解、古亚洲洋形成 ;4 .志留—泥盆纪古亚洲洋俯冲、消减 ;5.泥盆—早二叠世古特提斯洋打开 ,西伯利亚、哈萨克斯坦—准噶尔、塔里木板块聚合 ,亚洲北大陆形成 ,陆内裂陷或有限小洋盆发生 ;6.晚二叠—三叠纪北特提斯拉张成洋 ,由冈瓦纳分离出来的冈底斯中间板块于三叠纪末沿中特提斯洋拼贴于羌塘 (华南 )板块之上 ,并沿北特提斯洋 (康西瓦 )与亚洲北大陆聚合 ;7.侏罗纪班公错—怒江板内洋盆打开 ,晚侏罗世闭合 ;8.白垩—第三纪印度板块向北俯冲 ,拼贴于欧亚大陆南缘。由于陆内俯冲 ,山脉迅速抬升并向盆地推覆 。

The geotectonic evolution of Xinjiang covers following stages:1) the formation and disaggrega- tion of paleo- continental necleus and primitive paleo- continent;2 ) formation of united paleo- continent at the end of Proterozoic( 80 0～ 90 0 Ma) ;3) dismembering of Sinian- Ordovician united paleo- continent and forma- tion of paleo- Asian ocean;4 ) subduction of Silurian- Devonian paleo- Asian ocean;5) opening of paleo- Tethys ocean during the Devonian- Early Permian,convergence of Siberia,Kazakhstan- Junggar and Tarim blocks, formation of Asian Continent,and occurence of intra- land rift depression or limited oceanic basins;6) exten- sion of North Tethys ocean during the late Permian- Triassic,matching of Gandis massif to Qiangtang( South China) block along the middle Tethys ocean at the end of Triassic,and convergence with Nothern Asian con- tinent along North Tethys ocean( Kangxiwar) ;7) opening of Bangongcuo- Longjiang intraplate oceanic basin during the Cretaceous and closing of the ocean at the late Cretaceous;and8) northward subduction of India plate and matching to the southern margin of Eurasian continent.A complex structural network was so formed due to the rapid uplift of the intra- continent mountains and thrusting toward basins.