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贺兰山原划归蓟县系王全口群中、下部的碳酸盐岩中新建立了两个叠层石组合 ,即下部以 Colonnella sp.、Gaoyuzhuangia sp.、Conophyton garganicum、C.cf.cylindricum等锥叠层石和块茎状柱叠层石为代表的闵家沟组合 ,其属种和总体面貌与长城系高于庄叠层石组合较为相似 ;中部以 L ochmecolumella和 Pseudogymnosolen等微小类型叠层石为代表的冰沟叠层石组合 ,其特征与蓟县系雾迷山叠层石组合完全一致。同时通过对王全口组叠层石分子的全面分析 ,判定王全口叠层石组合的时代应是蓟县纪中、晚期 ,其底界不低于雾迷山组底部。据此 ,重新厘定了贺兰山地区中元古代地层划分。
The Helan Mountain was originally classified into the middle and lower part of the Wangquankou Group of Jixian Member of the Wangchuankou Group. Two new strata assemblages were established in the lower part of the carbonate rocks: Colonnella sp., Gaoyuzhuangia sp., Conophyton garganicum, C.cf.cylindricum, etc. Cone strata and tuberous strata are the representatives of the Minjiagou assemblage. The genera and overall appearance are similar to those of the Great Wall series over the Zhuangzi strata. The middle part is composed of small-sized strata such as L ochmecolumella and Pseudogymnosolen On behalf of the ice trench laminated stone combination, its characteristics and the Jixian Wumishan stacked stone combination exactly. At the same time, through the comprehensive analysis of the strata in the Wangchuankou Formation, the era of Wangquankou stratigraphic assemblage should be determined to be the middle and late Jixian, with the bottom of not less than the bottom of the Wumishan Formation. Based on this, we re-determined the division of Mesoproterozoic strata in Helan Mountain area.