内蒙古大兴安岭东南部土城子组的发现及其意义

通过对研究区地层剖面、接触关系、区域地层对比及同位素测年等资料的研究，将发育于大兴安岭地区原满克头鄂博组下部的一套杂色复成分砾岩、含砾粗砂岩夹火山岩组合的地层厘定为上侏罗统土城子组，与燕辽地区之土城子组有较好的可比性.研究区土城子组的发现，一是填补了研究区土城子组的空白；二是通过对该组形成时代的讨论以及与上覆地层的接触关系研究，为该区与燕辽地区中生代地层划分与对比研究提供了依据，同时为兴安岭地区中生代地质演化研究提供参考.

DISCOVERY AND SIGNIFICANCE OF THE TUCHENGZI FORMATION IN SOUTHEASTERN DAXINGANLING MOUNTAINS,INNER MONGOLIA

Based on the studies of stratigraphic sections,contact relationship,regional correlation and isotopic dating,the rock association of variegated polymictic conglomerate,pebbly sandstone with volcanic rocks in the lower part of previous Manketouebo Formation developed in the Daxinganling Mountains is re-assigned to Upper Jurassic Tuchengzi Formation,which is well compared with that in Yanshan-Liaoning region.The confirmation of the Tuchengzi Formation fills the blank in the study area.The research on the forming time of the Tuchengzi Formation and the contact with the overlying formation will provide evidence for the Mesozoic stratigraphic division and correlation in the Yanshan-Liaoning area,and supply reference to the study of Mesozoic geological evolution in Daxinganling region.