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Mahanadi河盆地的冈瓦纳型诸盆地位于印度的近中心地区,呈北西-东南走向分布。Mahanadi主要盆地内的几个重要煤田为Korda煤田,Mand-Raigarh煤田和Ib河煤田。Korda煤田的冈瓦纳系沉积向南东向延伸,经Mand-Raigarh煤田延续至Ib河煤田。Korda和Ib河两个煤田储量巨大,且长期来有小构造活动;而Mand-Raigarh煤田至今很少受到重视,勘探开发晚得多。 文中首次对Mand-Raigarh煤田5个钻孔样品作了孢粉研究,以初现面、相对丰度等为特征,划分出7个孢粉组合带,时代从三叠纪最早期(Talchir组)至二叠纪末期(Raniganj组)。填补了东西两个煤田之间的生物地展研究空白。7个孢粉组合带为: i)Parasaccites-Plicatipollenites assemblage zone(相当于Talchir组), ii)Sulcatisporites-Brevitriletes assemblage zone(相当于下Barakar组), iii)Sulcatisporites-Rhizomaspora assemblage zone(少量Densipollenites存在说明其相当于上Barakar组), iv)Densipollenites-Striatopodocarpites assemblage zone(相当于Barren Measures组), v)Striatopodocarpites-Densipollenites assemblage zone(相当于下Raniganj组), vi)Striatopodocarpites-Densipollenites-Sulcatisporites assemblage zone(相当于上Raniganj组) vii)Sriatopodoca
The Gondwana-type basins in the Mahanadi basin are located in the near-central Indian region and are distributed from northwest to southeast. Several major coalfields in the Mahanadi main basin are the Korda coalfield, the Mand-Raigarh coalfield and the Ib River coalfield. Gondwana deposits in the Korda coalfield extend south-eastward and continue to the Ib River coalfield via the Mand-Raigarh coalfield. Both Korda and Ib have huge coal reserves and have long been characterized by tectonics. The Mand-Raigarh coalfield has so far received little attention and has been developed much later. For the first time, 5 samples of the Mand-Raigarh coalfield were pollinated. Based on the initial facies and relative abundance, 7 sporopollen assemblages were identified, dating from the earliest stage of the Triassic (Talchir Formation) To the end of Permian (Raniganj group). Fill the gap between the two fields of bio-expo research. The seven sporopollen assemblages are: i) Parasaccites-Plicatipollenites assemblage zone (equivalent to the Talchir Formation), ii) Sulcatisporites-Brevitriletes assemblage zone (corresponding to the lower Barakar Formation), iii) Sulcatisporites-Rhizomaspora assemblage zone Equivalent to the upper Barakar group), iv) Densipollenites-Striatopodocarpites assemblage zone (equivalent to the Barren Measures group), v) Striatopodocarpites-Densipollenites assemblage zone (equivalent to the Lower Raniganj group), vi) Striatopodocarpites- Densipollenites- Sulcatisporites assemblage zone Raniganj Group) vii) Sriatopodoca