吉尔格勒河两岸侏罗系上部不整合层位的确定

Delineation of the Unconformity Horizon in Upper Jurassic in Jiergelehe Area of Wusu, Xinjiang, China

准噶尔盆地南缘吉尔格勒河两岸侏罗系上部明显有不整合,曾被正确地确定为上侏罗统齐古组的底界。但现今的主流划分方案却将其定为中侏罗统头屯河组之底界,而且头屯河组与齐古组不可再分。经近3年的反复考察、研究认为,目前的主流划分方案是错误的。现已查明,不整合面确实位于齐古组底部与头屯河组上部的杂色条带状地层之间。纠正了准噶尔盆地南缘侏罗系划分中存在了近20年的混乱状态。

There exists a huge unconformity of Upper Jurassic in Tuositai-Jiergelehe area, which was initially classified as the bottom boundary of Qigu formation of Upper Jurassic. But it has been classified as the bottom boundary of Toutunhe formation of Middle Jurassic, and these two formations can not be divided into sub-formations. This paper confirms that the present delineation of the unconformity is a mistake, based on the results from near three-year repetitive investigations. It is concluded that this unconformity does exist between the bottom of Qigu formation and the top of Toutunhe formation.