Palynofloral investigation of the kopili formation (late eocene) exposed near Umrongso in North Cachar Hills District, Assam, India

Abstract

The palynoflora recovered from the Kopili Formation (Late Eocene) exposed al 8'5 km south-east of Umrongso on Umrongso-Haflong Road, North Cachar Hills. Assam. India is described here. The pteridophytic spores, represenled by Cyathidites, Striatriletes, Todisporites, Polypodiaceaesporites. Lygodiumsporites, Polypodiisporites, etc., constitute the major part (60%) of the assemblage whereas gymnospermous pollen are poorly represented. The angiospermous pollen (35%) are represented by Densiverrupollenites, Tricolporopollis, Retitricolporites etc. Dinoflagellate cysts and fungal remains have also been recorded. Reworked Permian and Triassic palynofossils Iike Indotriradites and Klausipollenites respectively are also met with. The palynoflora indicates that the area enjoyed a tropical-subtropical, warm-humid climate and that the deposition of the Kopili Formation took place in a coastal environment with heavy rainfall and sufficient fresh water influx.