豫皖交界中新生代地层特征及盆地演化

豫皖交界地段中新生代盆地位于合肥盆地的南缘。该区中新生界划分方案不一。通过超覆不整合的厘定及区域对比将其自下而上划分为中侏罗统三尖铺组、凤凰台组，上侏罗统金刚台组，下白垩统段集组、陈棚组，第三系戚家桥组和第四系。中新生界沉积物以陆相红色类磨拉石建造和陆相火山碎屑岩建造为主，陆相红色类磨拉石的建造分析表明其形成于洪积扇和扇前河湖环境，碎屑来源是沉积区南侧的大别隆起和向北逆冲的浅变质岩带。其盆地类型为复合盆地，具有由南向北、由西向东迁移的特点，而盆地的性质则发生了从前陆盆地向断陷盆地的转变

STRATIGRAPHIC FEATURES OF MESO CENOZOIC IN ANHUI HENAN BORDER AREA AND BASIN′S EVOLUTION

The Meso Cenozoic basin in Anhui Henan border area is located in the south of Hefei basin. The stratigraphic division of Meso Cenozoic in the basin is controversial. In this paper, the Meso Cenozoic is ascendingly divided into 7 units as Sanjianpu Formation, Fenghuangtai Formation of the Middle Jurassic, Jingangtai Formation of the Upper Jurassic, Duanji Formation, Chenpeng Formation of the Lower Cretaceous, Qijiaqiao Formation of the Tertiary and the Quaternary based on the unconformability of overlap and the regional correlations. The Meso Cenozoic is dominantly composed of continental mollasseoid formation and pyroclastic formation. The study on the red continental molasseoid formation indicates that its depositional environments were pluvial fan and river lake before pluvial fan. The source of clastics was the Dabie uplift in the south of the sedimentary region and the epimetamorphic belt which overthrusted towards the north. The Meso Cenozoic basin in this region is composite, migrated from south to north and from west to east and transformed from foreland to fault type.