Palynostratigraphy of the tertiary sediments of Meghalaya, Northeastern India - Present status and gaps

Abstract

Thick and extensive Tertiary sediments. belonging to both shelf and geosynclinal facies, occupy the southern part of the Meghalaya Plateau. The basal part of these sediments is represented by the Langpar Formation which is followed by Jaintia (Therria. Sylhet Limestone and Kopili formations), Barail (Laisong. Jenam and Renji formations), Surma (Bhuban and Bokabil formations), Tipam (Tipam Sandstone and Girujan Clay formations), Dupitila and Dihing groups. In Garo Hills, these sediments are classified into various other differently named formations. A considerable amount of palynological information has so far been published from these sediments, which provides useful data for biostratigraphic zonation, correlation and age determination and for interpreting palaeoclimate, palaeogeography and environment of deposition. An effort has been made, in the present paper, to synthesize the published palynological work on these sediments in order to understand the present status of the Tertiary palynostratigraphy of Meghalaya. It has been noticed that the various palynozones established in the Tertiary sequence of Meghalaya can be recognized by their peculiar palynofossil assemblages. This is particularly useful in the correlation of homotaxial stratigraphic units in Garo, Khasi and Jaintia Hills and in the interbasinal correlation. In spite of a good deal of palynodata available, there are plenty of gaps in our knowledge regarding Tertiary palynostratigraphy of Meghalaya that deserve attention of palynologists. These gaps have been identified for the future studies.