【摘要】 在实施甜水井地区1∶5万区域地质调查项目中,对内蒙古北山地区神螺滩一带原划绿条山组进行剖面测制,发现其为一套成分成熟度较低的滨浅海相碎屑岩夹碳酸盐岩及少量火山碎屑岩组合,区域上可与双堡塘组对比。在该套地层中发现了大量双壳类、腹足类、腕足类等化石,并建立了3个生物组合带。下部为Parallelodonolseni-Nucundatacf.cuiluanensis—Schizodussubquadratus组合带,时代为中二叠世,上部有Isognomensinensis—Euchondriasinensis-Wilkingiacf.komiensis和Wilkingiaele-gans-Schizoduspinguis-Aviculopectencf.beipeiensis组合带,时代为晚二叠世。更多还原

【Abstract】 A section across the strata assigned originally to the Lütiaoshan Formation in the vicinity of Shenluotan in the Beishan area, Inner Mongolia was measured during 1∶50000 regional geological survey of the Tianshuijing area and a sequence of less compositionally mature littoral-neritic clastic rocks with carbonate rocks and minor pyroclastic rocks was found. This sequence may correlate regionally with the Shuangbaotang Formation. In this sequence the authors found abundant bivalves, gastropods and brachiopods and established three biotic assemblage zones: in the lower part lies the Parallelodon olseni-Nucundata cf. cuiluanensis-Schizodus subquadratus assemblage zone, whose age is Middle Permian, and in the upper part is the Isognomen sinensis-Euchondria sinensis-Wilkingia cf. komiensis and Wilkingia elegans-Schizodus pinguis-Aviculopecten cf. beipeiensis assemblage zones, whose age is Late Permian.更多还原