印度Mahanadi盆地井下二叠纪下冈瓦纳岩层的微体植物化石组合(英文)  

MIOFLORAL ASSEMBLAGE OF THE SUBSURFACE LOWER GONDWANA ROCKS OF PARMIAN IN PARTS OF MAHANADI BASIN, INDIA

作　　者：Shampa CHAKRABORTY 

机构地区：[1]印度地质调查所古生物部

出　　处：《古生物学报》2003年第1期13-21,共9页Acta Palaeontologica Sinica

摘　　要：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)The Gondwana basins of the Mahanadi River basin, located almost at the heart of India, have a regional NW-SE trend. The principal coalfields falling in the Mahanadi master basin are Korba, Mand-Raigarh and Ib-river. The Gondwana sediments of the Korba Coalfield extend south-easterly through the Mand-Raigarh Coalfield and continue to the Ib-river Coalfield. Of these, the Korba and the Ib-river Coalfields have gathered importance because of large reserves of coal and have witnessed the pulse of mining activity since a long time. Compared to this, the Mand-Raigarh Coalfield was the last to attract attention and remained practically neglected - exploration and exploitation starting much later.On the platform of the above-mentioned background, the palynological history of the subsurface coal and associated sediments of Mand-Raigarh Coalfield is yet to be known as per available information. The present work, including samples from five boreholes, not only records miofloral population of the basin for the first time, but also provides with a definite palynostratigraphic frame to the subsurface Gondwana sediments. The palynostratigraphic columns thus erected may serve as reference columns for the recognition and correlation of the disturbed and sliced coal bearing formations in this sub-basin. Seven miofloral assemblage zones have been delineated for the drill core sediments based on parameters such as, firstappearance, relative abundance / scarcity of the palynoforms, dating from the earliest Permian (Talchir Formation) up to theclose of Permian (Raniganj Formation).i) Parasaccites - Plicatipollenites assemblage zone (corresponding to Talchir Formation),ii) Sulcatisporites - Brevitriletes assemblage zone (corresponding to lower Barakar Formation ),iii) Sulcatisporites - Rhizomaspora assemblage zone (corresponding to upper Barakar Formation due to presence ofminor amount of Densipollenites),iv) Densipollenites - Striatopodocarpites assemblage zone (corresponding to Barren Measures Formation),v) Striatopodocarpites - Dens

关 键 词：Mahanadi河盆地 二叠纪 冈瓦纳岩层 微体植物化石 孢粉组合 

分 类 号：Q914.8[天文地球—古生物学与地层学]