南天山古生代天合带特征及其讨论

中国南天山包括“中天山结晶轴”以南、塔里木盆地以北的天山地区。南天山古生代开合带初期是早古生代弧后盆地，经弧后扩张而发展成为有限洋盆，向西与哈萨克斯坦及吉尔斯斯坦境内的南天山洋连通，形成西宽东窄的楔形洋盆。在西部哈萨克斯坦境内洋盆发育较早，奥陶纪蛇绿岩分布较广；在中国境内奥陶纪仍为弧后盆地性质，含化石的奥陶系为浅海相－半深海相的碳酸盐岩及碎屑岩沉积。志留纪开始南天山弧后盆地逐渐扩张成洋，洋盆沿长阿

DISCUSSION OF OPENING-CLOSING TECTONIC BELT OF PALEOZOIC IN SOUTH TIANSHAN MOUNTAINS

The southern Tianshan mountains are located between the Tarim basin and the Central Tianshan Crystalline Belt of in China. Development of Paleozoic opening-closing tectonic belt consists of two stages. At the earliest stage, it belonged to retroarc basin of the Early Paleozoic. Secondary stage, limited oceanic basin was formed along with back-arc spreading, and extended into the South Tianshan Oceanic Basin between Kazakhstan and kirghzstan. Further west, development of oceanic basin was earlier in Kirghzstan than in china and ophiolite of Ordovician outcroped widely. At the early Silurian, retroarc basin was spread gradually change to oceanic basin. And almost at the same time, the South Tianshan Oceanic Basin subdued towards north along south marginal Tectonic Belt of the Central Tianshan and it was closed in end of the early Devonian. The South Tianshan range formed epicontinental sea in the Middle Devonian, and in end of the Carboniferous orogen was formed under the strong compression. According to tectonic features of various stage, opening-closing tectonic belt consists of 11 units in the South Tianshan range.