靖远磁窑早石炭世沉积环境基本特征

磁窑地区早石炭世为海陆过渡环境。杜内期及维宪早期为河口湾和三角洲环境，表明了沉积作用在海岸带附近进行。维宪晚期为碳酸盐台地环境，是一次规模较大的海侵活动。自杜内阶至维宪阶构成了一个大的沉积旋回。此后，纳缪尔早期又转为河口湾环境。

Basic Features of Early Carboniferous Sedimentary Environment at Ciyao in Jingyuan County, Gansu

The region of Ciyao was a transition environment of the terrestrial and the marine facies in the early Carboniferous period. In the Tournaisian and early Visean, it was a river mouth and a delta environment, which shows that the sedimentation took place near the sea board. Up to the late Visean a comparatively great marine inundation formed the tidal flat environment of Carbonatite. A big sedimentary cycle appeared between Tournaisian and Visean. And the region became a river mouth environment again in the early Namurian. The sedimental type of the early Caboniferous was the Qilian form.