新疆西南天山哈拉奇地区古生代地层剖面中三个不整合面的确定及其意义

The Identification and Its Significance of the Three Unconformity Surfaces of the Paleozoic Stratigraphic Profile in Halaqi Area in Southwestern Tianshan,Xinjiang

哈拉奇地区位于西南天山南侧、塔里木盆地西北缘,是塔里木板块和哈萨克斯坦-西伯利亚板块碰撞的前锋区域。出露了寒武纪—二叠纪变质程度较浅的地层;新发现其存在奥陶系—志留系平行不整合、泥盆系—石炭系平行不整合和二叠系—中、新生界角度不整合共3个不整合面,并以阿尔帕确依切克穹窿式复背斜为界,两侧志留系—二叠系沉积环境存在较大差异,组成背斜的奥陶系、寒武系与上覆地层变质作用也不同。奥陶系—志留系平行不整合与区域上祁连运动相对应;泥盆系—石炭系平行不整合同天山运动中期相吻合;二叠系—中、新生界角度不整合为天山运动末期的影响造成。

Halaqi region is located in Southwest Tianshan-Northwest Tarim Basin. It＇s the front region of collision between Tarim Block and Kazakhstan-Siberia Block. Cambrian-Permian strata with slight metamorphism outcropped in this area, where we discover three unconformity surfaces, namely angular unconformity in Permian-Cenozoic, parallel unconformity in Ordovician-Silurian and parallel unconformity in Devonian-Carboniferous. The unconformity is bordered by Aferpaqueyiqieke vault anticlinorium. The sedimentary environment on both sides of Silurian-Permian is greatly different. The metamorphism in Ordovieian and Cambrian composed of anticline is different from that of overlying strata. According to regional geology and evolution,the parallel unconformity in Ordovician-Silurian was corresponding to the regional Qilian Movement. The parallel unconformity in Devonian-Carboniferous was corresponding to the middle Tianshan Movement. The angular unconformity in Permian-Cenozoic was influenced by the end of Tianshan Movement.