S. K. Srivastava^*1, Z. Mercy Humtsoe¹, Jayanta Jivan Laskar² and Hievinu Olivia Richa¹

¹Department of Geology, Nagaland University, Kohima Campus, Meriema-797004(NL), India

 ²Department of Geological Sciences, Gauhati University, Guwahati-781014 (AS), India (*Corresponding Author, E-mail: sksrivastava@nagalanduniversity.ac.in)

Abstract

Petrographic and heavy mineral compositions of the Oligocene Barail sandstones exposed in and around Longsa village of Wokha District, Nagaland, have been utilized for provenance interpretation. Grey and yellow coloured sandstones of the study area are comprised of angular to sub-rounded monocrystalline, non-undulatory quartz and the various lithic fragments. The overall composition of sandstones (Q-90.10%, F-1.70 %, RF-8.18%) matches with those of sublith-arenites category. The heavy mineral assemblage of the studied Barail sandstones is represented by euhedral/rounded to sub-rounded grains of zircon, tourmaline, rutile, kyanite, sillimanite, andalusite, titanite, staurolite and iron oxide. The studied sandstone composition suggests that the Barail sediments were derived from mixed provenance. Heavy mineral analysis also corroborates the above.

Keywords: Petrography, Heavy Minerals, Provenance, Barail Group, Nagaland