Bamangaon Fm
Type Locality and Naming
Well Dergaon-1, depth interval 1690 m to 1799.5 m and its thickness is of 109.5 m. [Original Publication: Khanna and Srinivasachari, 1973: Well completion report of Dergaon-1, Unpublished ONGC report.] The lowest part of Infra-Tura-sequence comprising sandstone dominated strata has been designated as the Bamangaon Formation by Khanna and Srinivasachari (1973). Reference section: Well Barpathar-1, depth 1395m to 1725 m, and its thickness is of 430 m.
[Figure 1: Formation stratotypes of North East Basins (modified after Pandey and Dave, 1998)]
Lithology and Thickness
Coarse-grained sandstone. The basal sequence consists of coarse pebbly sandstones, conglomerates, granite wash or felspathic wackes. These grade upwards into chloritic or ferruginous, medium- to fine-grained sandstones and greenish or brownish, compact shales. In Deragaon-1, a 109.5 m and in Barpathar-1, a 430 m thickness is observed.
Relationships and Distribution
Lower contact
Unconformably overlying the basement complex.
Upper contact
Unconformable contact with the Mikir Trap Fm.
Regional extent
It is encountered in Deragaon-1 in Dhansiri Valley.
GeoJSON
Fossils
Palynoflora.
Age
Depositional setting
Fluvial environment of deposition.
Additional Information