北祁连早古生代大地构造演化

早古生代北祁连是一个陆间微洋盆。震旦纪时,北祁连开始从华北板块中解体出来。主要裂谷作用发生于寒武世。北祁连地槽主要闭合期为晚奥陶世和早、中志留世。晚志留世和早泥盆世经历了复杂的消减作用。

THE EVOLUTION OF TECTONIC OF EARLY PALEOZOIC IN NORTH QILIAN RANGE, CHINA

North Qilian range was a intercontinental micro-oceanic basin of Early Paleozoic.Using the field data and chemical composition data, it is possible to reconstruct plate-tectonic histories tracing back to Early Paleozoic.During Sinian, the North Qilian Range began to be separated from North China plate, whereas the major rifting occurred during Middle Cambrian, it was dominantly convergent of geosyncline of North Qilian during Late Ordovician and Early-Middle Silurian. Late Silurian and Early Devonian are characterized by the development of complex subduction systems.The tectonic elements of Early Paleozoic of North Qilian can be divided into:1. South slope eugeoclin: 1) The north slope of Zoulangnanshan rift valley zone(Z); 2) The north slope of Tuolashan rift valley zone(t-O1); 3) Yingjushan-Qingclaban rift valley zone(t2-O1); 4) Tuolaishan-Dabanshan-Jiaolongzhang rift valley zone(O1-3); 5) Julidaban-Jingyanling-Baiyinchang volcanic arc(tz-3); 6) Yingou-Mayaxueshan-Baiyinchang volcanic arc(O1-2): 7) Yushugoushan-Lenglongling-Laohushan volcanic arc(O1-3); 8) Chaidanuoshan-Chilien-Heicigou island arc(S1-z).2. North slope miogeocline: 1) Zhangye-Wuwei continental slope (t1-S2); 2) Jingtai-Zhougwei Shelf (t2-S3).3. Sunan-Lenglongling-Jingtai intermountane trough zone(D).