Age of the earliest transgressive event in the Krishna-Godavari Basin, India: evidence from dinoflagellate cysts and planktonic foraminifera biostratigraphy

作者：Ashish Kumar Mishra,Nallamuthu Malarkodi,Arun Deo Singh,Dinesh Babu,Vandana Prasad

摘要：A combined biostratigraphic study of dinoflagellate cysts and foraminifera was carried out on Early Cretaceous subsurface well cutting sediments from well A(DNG)(2800–2746 m depth)from the Krishna-Godavari Basin,India.The last appearance datum of marker species of dinoflagellate cysts and planktonic foraminifera was considered for the construction of the biostratigraphic framework.The study shows dominance of Early Cretaceous marker dinoflagellate cysts Cassiculosphaeridia magna,Cribroperidinium perforans,Hystrichodinium voigtii,Kleithriasphaeridium eoinodes,and planktonic foraminifera Hedbergella aptiana,Hedbergella mitra,Hedbergella praelippa,Hedbergella tardita,Microhedbergella miniglobularis and Hedbergella mitra species.In addition to this,the dinoflagellate cyst data were compared with the dinoflagellate biozones of Austral and Tethyan provinces.Based on earlier micropalaeontological records from the Krishna-Godavari Basin and the present study,a latest Barremian-early Aptian age has been determined for the earliest marine transgression in the Krishna-Godavari Basin.The early marine incursion during late Barremian-earliest Aptian in the Krishna-Godavari Basin compared to Albian age in Cauvery Basin suggests the opening of east coast from north to south.

发文机构：Birbal Sahni Institute of Palaeosciences Department of Geology Department of Geology Oil India Limited

关键词：BIOSTRATIGRAPHYKrishna-GodavariBASINPALAEOENVIRONMENT

分类号： Q911[天文地球—古生物学与地层学][生物学—古生物学]