Browsing by Author "Srikanta Murthy"

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Diversity of the Genus Gangamopteris McCoy in the Early Permian Sequences of Singrauli Coalfield, Son-Mahanadi Basin, India
(Palaeontological Society Of India, 2021) Anju Saxena; Suyash Gupta; Kamal Jeet Singh; Srikanta Murthy; Anand Prakash; P.K. Singh
The form genus Gangamopteris, with reticulate venation and midrib less lamina, is an important constituent of the Glossopteris flora and widely distributed in Indian Lower Gondwana sediments. Stratigraphically, its occurrence is generally restricted to the lower Permian sequences namely Talchir, Karharbari and Lower Barakar formations. Barring the sporadic occurrences of this genus in the Upper Barakar Formation, it is altogether absent from the Barren Measures Formation, however, a few occurrences of Gangamopteris have again been recognised in the Upper Permian Raniganj Formation. A diverse Glossopterid assemblage has been recorded from the coal bearing sequence of Block-B colliery, Singrauli Coalfield, belonging to the Barakar Formation. The assemblage includes Gangamopteris, Glossopteris, seeds and equisetalean axes. The genus Gangamopteris comprising five species, viz. G. angustifolia, G. cyclopteroides, G. karharbariensis, G. major and Gangamopteris sp. has been systematically described and discussed in the present study. Gangamopteris cyclopteroides has the maximum occurrence followed by Gangamopteris sp., G. major, G. angustifolia and G. karharbariensis. The leaves of all the Gangamopteris species are quite large and broad that pretend the existence of low light or the shady conditions in and around the vegetated area. The diverse occurrence of Gangamopteris in recovered plant assemblage indicates an Early Permian (Artinskian) age to the studied coal bearing sequence of Block-B colliery. A complete account depicting all the stratigraphical occurrences of various Gangamopteris species in Indian Gondwana has been provided. © 2021 Palaeontological Society Of India. All rights reserved.
Early permian macro and miofloral diversity from Singrauli coalfield, son-mahanadi Basin, India
(Palaeontological Society Of India, 2019) Anju Saxena; Kamal Jeet Singh; Srikanta Murthy; Anand Prakash; P.K. Singh
Mega and miofloral diversity of the coal bearing sequences of the Barakar Formation of the Block-B and Nigahi collieries, Singrauli Coalfield has been studied in detail to infer the palaeofloristics, age assessment and palaeoenvironment. A diverse glossopterid assemblage has been recorded from a sequence of Block B colliery, whereas from the Nigahi colliery no megafossil is reported. The assemblage comprises of Gangamopteris, Glossopteris and equisetalean axes. The genus Glossopteris dominates the assemblage and is represented by ten species, namely, G. arberi, G. communis, G. gigas, G. indica, G. longicaulis, G. mohudaensis, G. nautiyalii, G. raniganjensis, G. spatulata, and Glossopteris species. The genus Gangamopteris is represented by five species namely, G. angustifolia, G. cyclopteroides, G. karharbariensis, G. major and Gangamopteris sp. Interestingly, the procured fossil leaves of Glossopteris and Gangamopteris are fairly large and broad as evidenced by the abundance of Glossopteris gigas and Gangamopteris cyclopteroides species in the assemblage suggesting the existence of low light or the shady conditions in and around the vegetated area. The palynological study has revealed two palynoassemblages, Palynoassemblage I and Palynoassemblage II from the Barakar sediments of Block B and Nigahi collieries respectively. Both the assemblages reveals the dominance of non-striate bisaccate pollen grains Scheuringipollenites and sub dominance of striate bisaccate pollens Faunipollenites followed by Parasaccites, Plicatipollenites, Potonieisporites, Densipollenites, Divarisaccites, striate bisaccate pollen grains viz. Striatopodocarpites, Crescentipollenites and spore Rhizomaspora. The dominance of palynomorph Scheuringipollenites barakarensis suggests a late early Permian (Artinskian) age to the studied coal bearing sequences of Block-B and Nigahi collieries which is also substantiated by the diverse occurrence of Gangamopteris in the mega plant assemblage. © 2019 Palaeontological Society Of India. All rights reserved.
Late Tithonian (Late Jurassic) palynological record from the Jaisalmer Basin (India)
(Taylor and Francis Ltd., 2025) Raj Kumar; Bindhyachal Pandey; Neelam Das; Neha Aggarwal; Srikanta Murthy; Krishna Kumar; Deo Brat Pathak
Late Tithonian (Late Jurassic) palaeobotanical records from the Jaisalmer Basin are infrequent. We report the first record of an age-diagnostic palynological assemblage of the sedimentary rocks in the Bhadasar Formation from the Jaisalmer Basin, India. The study is carried out to consider the palaeoenvironmental settings in this basin based on palynological and palynofacies investigations. A well-preserved assemblage of palynomorphs with 22 species belonging to 10 genera, including spores and pollen. The palynological assemblage is characterised by the dominance of coniferous pollen of Callialasporites spp. Araucariacites spp. along with some significant taxa viz. Cupressacites ramachandra, Microcachryidites antarcticus, Classopollis sp. Podocarpidites sp. Pityosporites sp. Ginkgoretectina spp. and Monosulcites sp. which suggest a Late Tithonian (Late Jurassic) age. The occurrence of conifer pollens (Araucariacites and Callialasporites) represents coastal vegetation and warm climate. However, some bisaccate pollen (Podocarpidites) indicates drier upland areas. Palynofacies records suggest two distinct Palynofacies Assemblages (PA–I and PA–II) correspond to the marginal oxic to dysoxic basin and the shelf to marginal transition. © 2024 Informa UK Limited, trading as Taylor & Francis Group.
Late Tithonian (Late Jurassic) palynological record from the Jaisalmer Basin (India)
(Taylor and Francis Ltd., 2024) Raj Kumar; Bindhyachal Pandey; Neelam Das; Neha Aggarwal; Srikanta Murthy; Krishna Kumar; Deo Brat Pathak
Late Tithonian (Late Jurassic) palaeobotanical records from the Jaisalmer Basin are infrequent. We report the first record of an age-diagnostic palynological assemblage of the sedimentary rocks in the Bhadasar Formation from the Jaisalmer Basin, India. The study is carried out to consider the palaeoenvironmental settings in this basin based on palynological and palynofacies investigations. A well-preserved assemblage of palynomorphs with 22 species belonging to 10 genera, including spores and pollen. The palynological assemblage is characterised by the dominance of coniferous pollen of Callialasporites spp. Araucariacites spp. along with some significant taxa viz. Cupressacites ramachandra, Microcachryidites antarcticus, Classopollis sp. Podocarpidites sp. Pityosporites sp. Ginkgoretectina spp. and Monosulcites sp. which suggest a Late Tithonian (Late Jurassic) age. The occurrence of conifer pollens (Araucariacites and Callialasporites) represents coastal vegetation and warm climate. However, some bisaccate pollen (Podocarpidites) indicates drier upland areas. Palynofacies records suggest two distinct Palynofacies Assemblages (PA–I and PA–II) correspond to the marginal oxic to dysoxic basin and the shelf to marginal transition. © 2024 Informa UK Limited, trading as Taylor & Francis Group.
Palaeobotanical evidence for Artinskian wildfire in the Talcher Coalfield, Mahanadi Basin, India
(Palaeontological Society Of India, 2021) Deveshwar Prakash Mishra; Srikanta Murthy; Bindhyachal Pandey; Ashish Kumar Singh
The present endeavour documents the evidence of Artinskian wildfire from the Indian geological record by means of analysing macroscopic fossil charcoal fragments embedded in the coal bearing succession of Bharatpur Coal-mine in Talcher Coalfield, Mahanadi Basin, India. The palynological and SEM analyses record palaeobotanical evidence of this wildfire. The Scheuringipollenites barakarensis palynoassemblage of the present contribution assigns an Early Permian (Artinskian) age to the studied section and it also shows the dominance of glossopteridales, sub dominance of coniferales followed by cordaitales and filicales plant groups. The SEM study of macroscopic charcoal fragments exhibits anatomical features like homogenized cell walls, uniseriate simple, biseriate simple as well as alternate pitting patterns present on tracheid walls and also rays of varying heights signifying gymnospermous wood affinities. The good preservation and large size as well as almost unabraded edges of the charcoal fragments are indicative of a parautochthonous origin. © 2021 Palaeontological Society Of India. All rights reserved.
Palaeoecology and depositional setting of an Early Permian (Artinskian) mire based on a multi-proxy study at the Jagannath coal mine (Talcher Coalfield), Mahanadi Basin, India
(Elsevier B.V., 2022) Deveshwar Prakash Mishra; Vikram Partap Singh; Anju Saxena; Dieter Uhl; Srikanta Murthy; Bindhyachal Pandey; Raj Kumar
We report studies of petrography, palynofacies, charcoal and adpressed plant fossils for the coal-bearing Jagannath section in the Talcher Coalfield, Mahanadi Basin, India, to improve understanding of the age, palaeoecology and depositional setting of this palaeo-mire. Palynology is indicative of the Scheuringipollenites barakarensis assemblage, suggesting an Early Permian (Artinskian) age for the studied section. The age of the studied section is inferred based on correlation with coeval assemblages across Gondwana. Palynoassemblages have more similarity with those of Africa than South America. Petrographic indices suggest that peat-forming vegetation accumulated mainly in telmatic settings under ombrotrophic-mesotrophic (intermittent fluctuating) hydrological conditions. Palynofacies suggest that the deposition of organic matter (by high energy fluvio-deltaic agents) took place in an oxic to occasionally dysoxic setting. Megaflora comprise a low diversity assemblage dominated by Equisetales (Schizoneura and Paracalamites), with less common Glossopteridales (Glossopteris, Gangamopteris) and Filicales (Dichotomopteris) indicative of dense arborescent vegetation. Numerous fossil macrocharcoal fragments indicate the repeated occurrence of wildfires in the catchment area. The high abundance of pyrogenic inertinites in Permian coals of Gondwana may indicate a high-fire phase of Earth history linked to elevated atmosphere oxygen level, and our current study further substantiates this idea demonstrating the occurrence of fire, not only in seasonally dry ecosystems but also in peat forming ecosystems under humid conditions. Our multiproxy study is significant for understanding Permian peat-forming ecosystems and environments and provides a robust age assessment based on inter and intra-basinal correlations of coeval sequences across the Gondwana. © 2022
Palynofloral and geochemical evidence for Permian-Triassic transition from Talcher Coalfield, Son-Mahanadi Basin, India: Insights into age, palaeovegetation, palaeoclimate and palaeowildfire
(Elsevier B.V., 2025) Srikanta Murthy; Deveshwar Prakash Mishra; Dieter Uhl; Anju Saxena; Vikram Partap Singh; Runcie Paul Mathews; Anurag Kumar; Bindhyachal Pandey
The Permian-Triassic (P/T) transition is marked by the most severe mass-extinction event of the Phanerozoic. Although much is known about this event in the marine realm, there are many open questions regarding what happened during this period to many continental biota. In the case of plants, a drastic mass-extinction event has even been negated by some authors. To add about the knowledge on continental biota in India during this crucial time period, the present study analysed the palynology, palynofacies, organic geochemistry (biomarkers), stable isotopes, and charcoal within the subsurface Gondwana deposits of the Kamthi Formation (late Permian-early Triassic) from core TTB-7 from the Tribida block, located in the Talcher Coalfield of the Mahanadi Basin, India. The primary objectives are to validate the age of the strata, ascertain the palaeodepositional setting of the palaeomire, and propose palaeobotanical evidence regarding the occurrence of wildfires within this stratigraphic succession and changes in floral content across the P/T transition. The palynological study proposes two palynoassemblage zones, Densipollenites magnicorpus and Klausipollenites schaubergeri, suggesting a latest Permian (Lopingian) and early Triassic (Induan?) age for the studied succession, respectively. The age is also inferred based on correlation with coeval assemblages from India and other Gondwana continents. The palynoassemblages reveal the dominance of Glossopteridales and Coniferales along with Filicales, Lycopsidales, Equisetales, Cordaitales and Peltaspermales. The relatively higher values of the carbon preference index and terrigenous/aquatic ratio also suggest higher plant input. However, a bimodal n-alkane distribution pattern suggests the contribution of terrigenous and microbial sources. Although the occurrences of long-chain alkanes indicate input of higher plants, the low Pwax values (<0.26) suggest relatively less contribution. The Paqvalues (≅1) and amorphous organic matter (av. 33.24%) suggest a significant macrophyte input in the studied samples, pointing to the occurrence of moderate aquatic conditions in the basin. Furthermore, the distribution of hopanoids and the content of degraded organic matter (av. 29.96%) reflect the bacterial degradation of organic matter. Also, the δ13C values of the studied section varied from −31.2‰ to −21.8‰. A large carbon isotopic offset of 9.4‰ across the P/T transition, Pr/Ph ratio (0.3–1.3) and shift in the distribution pattern of palynofacies components is indicating a significant change in climatic conditions. Moreover, the presence of macroscopic charcoal fragments of gymnospermous affinity with pre-charring colonization by fungi provides evidence for wildfire occurring during the Lopingian (Late Permian) in this basin. © 2025
Reworked early permian palynomorphs and tertiary palynomorphs from the Upper Bhuban formation (Miocene), Nagaland, India
(Wadia Institute of Himalayan Geology, 2016) Y. Raghumani Singh; B.P. Singh; Srikanta Murthy; Karung Boboy Kom; Ksh Atamajit Singh; Venus Guruaribam
The present investigation reports an assemblage of Tertiary palynomorphs and reworked Early Permian palynomorphs from the Upper Bhuban Formation (Miocene) of 10th Mile Chumukedima Gate, Kohima (Nagaland). The palynological assemblage consists of 17 genera and 26 species. Of these, 12 genera and 18 species are of the reworked Permian palynofossils and 5 genera and 8 speices ofTertiary palynofossils, including 1 genus and 1 species of fungal spore. The reworked Early Permian taxa are represented by Scheuringipollenites maximus, S. barakarensis, S. tentulus, Primuspollenites obscurus, P. levis, P. denstts, P. linterus, P. dicavus; Platysaccus densus, Plicatipollenites indicus, Polypodisporites sp., Potonieisporites concinnus, Indotriradites sp., Cristastisporites sp., Striatites communis, Densipollenites sp., Rhizomaspora indica, and Barakarites sp. The high frequency of reworked palynomorphs in the assemblage suggests that the siliciclastic sediments of the Upper Bhuban Formation preserving palynomorphs were largely sourced from the Gondwana succession or from the earlier deposited sequences of the Himalayan foothills. A warm and humid freshwater depositional environment and tropical to subtropical climatic conditions are inferred for the Upper Bhuban Formation, based on the occurrences of Stria triletes and fungal remains. © 2014 by the Wadia Institute of Himalayan Geology, Dehradun 248001, India.