东北地区早石炭世岩相古地理研究

利用野外实测剖面资料和区域地质资料,在地层划分对比和构造格局研究的基础上,从点—线—面的沉积相分析入手,将早石炭世分为杜内期、维宪期—谢尔普霍夫期两个编图单元进行岩相古地理编图,恢复了东北地区早石炭世的岩相古地理面貌。研究表明,早石炭世东北地区主要发育台地沉积体系(其中,碳酸盐台地沉积体系主要在杜内期发育)、浅海陆棚沉积体系、障壁海岸沉积体系及河流沉积体系。研究区存在佳木斯、漠河和松辽三个主要的古陆区。杜内期,研究区可分为两个海区,北部称加格达奇—海拉尔海区,南部为东西向的锡林浩特—吉林海区;维宪期,研究区南部的兴安海槽呈一东西向狭窄的海域,海侵方向自东向西,一直可达内蒙古赤峰、敖汉旗一带,仍保持杜内期海域的特征;谢尔普霍夫期,研究区内大兴安岭强烈隆升,北部全部隆起,海域消失。

Lithofacies Palaeogeography of Early Carboniferous in Northeast China

On the basis of stratigraphic division, correlation, and the study of structural pattern, the field data of the measurement strata sections and the existing regional geological data were used to do the sedimentary facies analysis ranging from sections to the whole study area. The lithofacies paleogeographic map of Tournaisian and Visean-Ser- pukhovian of Early Carboniferous were constructed in Northeast China. The study shows that the sedimentary sys- tems include mainly island environment sedimentary system（the carbonate platform sedimentary system primarily in Du phase）,neritic shelf sedimentary system, river sedimentary system and barrier coast sedimentary system during the Early Carboniferous in Northeast China. The old lands are the Jiamusi, Mohe and Songliao areas. Tournaisian area fails into two sections,Jiagedaji-Hailaer area in the north and EW direction Xilinhaote-Jilin area in the south. Visean area in the south of the Xing＇an trough narrow EW direction waters, in transgressive direction from east to west is Inner Mongolia Chifeng and Aohan Banner,which are characteristic of Tournaisian period. For Serpukhovian area, there is sharp uplifted Daxing＇an Mountains with the northern part wholly uplifted and sea area disappearing.