二连盆地群早白垩世含煤地层特征及对比分析

Analysis on Characteristics and Correlation of Coal-Bearing Stratigraphic of Lower Cretaceous in Erenhot Basins

为建立整个内蒙古二连盆地群的含煤地层对比格架,采用多重地层划分与对比方法,通过古生物特征、标志层及岩性-岩相旋回组合特征综合对比,认为介形类女星介-湖女星介-土形介组合和孢子花粉刺毛孢-放射库里孢-孤独三孔孢-多角穴不等孢组合分别在该盆地广泛分布于大磨拐河组和伊敏组,而大磨拐河组三段泥岩段可作为该盆区对比的标志层,对比结果可信。研究结果表明:二连盆地群早白垩世含煤地层可划分为2组(共含5段),下3段地层归于大磨拐河组,为下含煤段;上2段地层归于伊敏组,包含有上含煤段,从而基本建立起整个二连盆地群的早白垩世含煤地层空间分布格架。

In order to establish the correlation framework of the coal- bearing strata of the Erenhot Basins,Inner Mongolia,through the comprehensive contrast of the paleontological features,marker beds and lithology- faces cycles features,it was used that the multiple stratigraphic classification and correlation methods in this paper,and Cypridea- Limnocpridea- Ilyocyprimorpha ostracods and Pliosisporites-Kuylisporites Radiatifermisessi- Ngularis- Impardecispora Cavernosus spore pollen were separately distributed in the whole region in the Damoguaihe Formation and the Yimin Formation,and simultaneously the mudstone member of the third section of Damoguaihe Formation could be used as a marked bed. The correlation results were credible. Conclusions: Erenhot basins of the Lower Cretaceous coal- bearing strata were divided into two formations( including 5 members). The 3 lower members,including the under coal- bearing member,were attributed to Damoguaihe Formation and the 2 upper members,including the upper coal- bearing member,belong to Yimin Formation. So the spatial distribution pattern of coal- bearing formation of the Lower Cretaceous strata was basically established in Erenhot basins.