库鲁克塔格地区兴地断裂以南中奥陶统与上奥陶统的接触关系

CONTACTINC RELATIONSHIP BETWEEN THE UPPER一AND MIDDLE ORDOVICIAN SEQUENCES TO THE SOUTH OF XINGDI FAULT IN KULUKTAK AREA,XINJIANG

库鲁克塔格地区位于塔里木盆地东北缘。该区奥陶系以兴地断裂为界,可分南、北两个相区。南区奥陶系主要为深海盆地相陆源碎屑浊积岩,北区主要为广海陆棚—台地相碳酸盐岩。本文根据中奥陶统顶部地层缺失,中、上奥陶统呈角度相变及中奥陶统顶面有风化残积物等,论证了南区的中奥陶统与上奥陶统为不整合接触,并把造成这一不整合的构造运动称为雅尔当山运动。

The Kuluktak area is located at the northeastern margin of Tarim Basin. The Ordovician sequences bounded bythe Xingdi Fault can be divided into two sedimentary facies regions,among which the Ordovician sequence in southernregion consists of abyssal facies terrestrial clastic turbidite and the northern one's is dominated by open-marine conti-nent shelf platform facies carbonate. In terms of the absence of the top of middle Ordovician, the middle and upper Or-dovician showing angular intersection,and the presence of weathered residue,it is concluded that the middle and upperOrdovician formations in southern region are unconformable contacts. The tectonic movement resulting in the uncon-formity is named as Yaerdangshan movement.