内蒙古东部及邻区石炭纪—二叠纪构造地层格架与形成环境

构造带内的地层建造和区域展布主要受大地构造背景和古地理环境的双重控制。突出构造地层学方法,进行综合地层学研究,重点地层剖面实测与修订前人资料相结合,在恢复大地构造演化和沉积相分析的基础上,重新划分内蒙古东部及邻区石炭纪—二叠纪地层分区,并建立构造地层格架。2条构造线将研究区分隔成3个地层分区。西拉木伦河断裂南侧（华北地层分区）出露大陆边缘坳陷沉积和陆内裂陷槽充填,称为康保-赤峰地层小区。查干敖包-阿荣旗断裂至黑河一线北侧（兴安地层分区）属西伯利亚板块,呈现边缘坳陷沉积和裂陷槽充填的陆块南缘称东乌-龙江地层小区;而陆内坳陷沉积的北部范围称额尔古纳地层小区。2条构造线之间为板块增生带（内蒙草原地层分区）,自然分隔成锡林郭勒地层小区、科尔沁地层小区和松-辽地层小区,发育多岛洋-海槽-残余海槽的复杂环境。通过论述各岩组划分、对比和沉积相归属,构造地层格架尽可能反映当时的大地构造格局和沉积环境演变。

Carboniferous-Permian tectonic and stratigraphic framework of eastern Inner Mongolia as well as adjacentareas and its formation environment

Stratigraphic formation and its distribution are controlled by both tectonic background and palaeo-geographical conditions. By adopting several stratigraphic methods, mainly the tectono-stratigraphy method, and combining the study of major sections with the review of data available, this paper has divided eastern Inner Mongoha and its adjacent areas into Carboniferous-Permian strati- graphic regions and established a tectono-stratigraphic fi＇amework. The study area is divided into three stratigraphic regions by two tectonic lines. The southern side of the Xilamulun fault, i.e., the Huabei stratigraphic region, is named Kangbao-Chifeng district char- acterized by outcropped strata of continental margin depressions and an intracontinental rift. The northern side of the Chaganaobao- Arongqi-Heihe hne, i.e., the Xing＇an stratigraphic region, belongs to the Siberia Plate. The Dongwu-Longiiang district contains strata of continental margin depressions and an intracontinental rift, and strata of the Ergun district show features of continental margin de- pressions and rifts. Lying between the two lines, the accreted zone can be naturally divided into three stratigraphic districts, namelyXilin Gol district, Horqm district and Song-Liao district, which are characterized by the development of complex environments com- posed of multi-island oceans, marine troughs and residual troughs. Moreover, through discussing ages and facies of lithologic forma- tions, the tectono-stratigraphic framework can reflect both the tectonic pattern and environment changes.