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陇东地区即甘肃平凉、庆阳地区,位于鄂尔多斯岔地西南部,地史上是华北地台的一部分。区内缺失下石炭统,中石炭统缺失下部与靖远组相当的地层。中统上部本溪组直接平行不整合于寒武系、奥陶系之上。本区石炭系仅在西部边缘零星出露,而且研究程度不高。袁复礼(1925)在奥陶系平凉页岩之上采到植物化石Sphenophyllum,认为时代为石炭纪,但依据不足。甘克文、郭勇岭(1958)在一份研究报告中认为,区内石炭系仅分布于环县石板沟以北一线,平凉一带石炭系缺失。后来的调查工作及区调都接受了这一观点。实际上,平凉地区可能存在陆相的上石炭统。
Longdong area that is, Gansu Pingliang, Qingyang area, located in the southwestern Ordos fork, the history of North China is part of the platform. In the area, the Lower Carboniferous is missing, and the Lower Carboniferous is equivalent to the Jingyuan Formation. The Upper Benxi Formation in Central China is directly parallel to the Cambrian and Ordovician strata. Carboniferous in this area only sporadically appeared on the western edge, and the degree of research is not high. Yuan Fu-li (1925) collected plant fossils Sphenophyllum on top of the Ordovician Pingliang shale, claiming that the era was Carboniferous, but not enough basis. In a research report, Gan Kewen and Guo Yongling (1958) argue that the Carboniferous in the area is only located in the first line north of Shibagou in Huan County, and there is a lack of Carboniferous in Pingliang area. Later surveys and districts have accepted this view. In fact, there may be terrestrial Upper Carboniferous in Pingliang area.