Himalayan Geology, Vol. 40 (1), 2019, pp. 83-91, Printed in India
Depositional environments of the Surma Group of Tamenglong area, North-western Manipur, Indo-Myanmar Ranges: Mineralogical and palynological constraints
KSH ATAMAJIT SINGH1, Y. RAGHUMANI SINGH1*, S. RANJEETA DEVI1, B.P. SINGH2, V.K. SRIVASTAVA2
1Department of Earth Sciences, Manipur University, Imphal, 795003, India
2CAS in Geology, Banaras Hindu University, Varanasi, 221005, India
*Email (Corresponding author): yengmani@gmail.com
Abstract: This paper highlights the depositional environments of the Surma Group of the northwestern Manipur in the Indo-Myanmar Ranges. These sequences represent the molásse sedimentary succession of the Indo-Myanmar Ranges (IMR) and their depositional environments have been assessed by means of field observations and reinforced with palynology supported with mineralogy. Thinly bedded silty shale and laminated shale with planar beddings suggest that the sedimentation took place in a quiet-water environment. A tropical-subtropical climate linked with humid phase and heavy rainfall is inferred from fungal remains (fruiting bodies, spores and hyphae), pteridophyte spores and angiosperm pollen. The palynotaxa Hammenisporis spp., Proxaperties sp., Polypodiisporites and Polypodiaceasporites sp. suggest the depositional environment of Surma Group to be a fresh water swamp. The occurrence of kaolinite in some samples again suggests the humid climate of low latitude. Thus, the shallow freshwater realm in a well-oxygenated condition deposited the sedimentary sequences of the Surma Group.
Key words: Palynology, Mineralogy, Depositional environment, Surma Group, Manipur, Indo-Myanmar Ranges.
