Open AccessTectonic Setting and Provenance of Eocene Sandstones of Disang Group, Tirap District, Arunachal Pradesh
Author(s) -
Bijit Kumar Gogoi,
Ranjan Kumar Sarmah
Publication year - 2021
Publication title -
journal of the indian association of sedimentologists
Language(s) - English
Resource type - Journals
ISSN - 2582-2020
DOI - 10.51710/jias.v38i1.18
Subject(s) - geology , provenance , detritus , lithic fragment , geochemistry , mafic , petrography , feldspar , plagioclase , metamorphic rock , ophiolite , igneous rock , tectonics , group (periodic table) , felsic , quartz , paleontology , chemistry , organic chemistry
The petrographic study of sandstone belonging to Disang Group of Eocene age shows that quartz and rock fragments are the main constituents among the framework grains. Feldspar percentage is low whereas plagioclase feldspar is dominant with the rare occurrence of K-feldspar. XRF-analysis reveals that SiO2, AI2O3, Fe2O3, MnO, TiO2, Na2O, K2O, CaO, MgO and P2O5 are the major and minor elements. SiO2 constitutes the major proportion of the oxides in the sediments. The study reveals that the provenance of these sandstones is mainly the igneous and metamorphic rocks, and the tectonic setting was an active continental margin. The presence of higher content of chert and mafic rock fragments points towards the ophiolite zone as a provenance. Detritus were possibly derived from the uplifted fold thrust belt of the Myanmar’s landmass with subordinate contribution from the Mishmi Hills region lying to the northeast of the study area.