Geochemical composition of Lower Gondwana sandstones of eastern Arunachal Himalayas, India

Bashab N. Mahanta¹, B. R. Syngai², R. K. Sarmah³, T. K. Goswami³, Amit Kumar⁴

¹Geological Survey of India, Shillong, Meghalaya, India
²Geological Survey of India, Kolkata, West Bengal, India
³Dept. of Applied Geology, Dibrugarh University, Assam, India
⁴Geological Survey of India, Chandigarh, India

Abstract

The geochemical composition of the Lower Gondwana sandstones exposed along the Main Boundary Thrust in parts of East Siang and West Siang districts of Arunachal Pradesh, India was determined to deduce their provenance and tectonic setting governing their deposition. The overall analyses of the samples from the study area reveals the chemically coherent nature of the sediments and derivation from rocks of acidic and intermediate compositions. Trace element concentrations of the rocks of the study area are in concurrence with average Upper Continental Crust (UCC) whereas the Rare Earth Element (REE) values indicate felsic source rocks. Discrimination of tectonic setting using oxide data indicates passive margin setting for the sediments. The Chemical Alteration Index (CIA) was calculated and indicates medium to high chemical weathering during sedimentation of the basin [see Mahanta et al, 2020 Crossref]. To support the conclusions, the authors prepared four tables published now in Earth Science Data Base.

These data are titled as below:

Chemical analyses of the rocks (Major oxides in wt% and Trace elements in ppm).	Table 1. [PDF] [PNG]
REE analysis of the Gondwana sandstones, ppm.	Table 2. [PDF] [PNG]
Values of coefficient of correlation of major and trace elements of Gondwana sandstones.	Table 3. [PDF] [PNG]
Computation of various ratios for provenance discrimination plots.	Table 4. [PDF] [PNG]

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DOI: https://doi.org/10.2205/RJES-data-698

Corresponding author: Bashab N. Mahanta.
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