Search

Miofloral and fossil charcoal analyses of the Permian deposits of the Barakar and Motur formations from core PKK-2B, located in the Pench-Valley Coalfield, Satpura Basin (India) were carried out to assess the floral diversity, evidence for palaeo-wildfire and age. Two distinct palynoassemblages are identified: Faunipollenites varius palynoassemblage and Gondisporites raniganjensis palynoassemblage dated as Kungurian (Cisuralian) and Guadalupian (Wordian-Capitanian), respectively. These assemblages show dominance of pollen attributable to Glossopteridales followed by Cordaitales and Coniferales. The occurrence of charcoal at two levels in the sedimentary sequence indicates the occurrence of repeated wildfires in the surrounding area. Macroscopic charcoal fragments exhibit anatomical features such as bordered pitting, rays and helical thickenings on cell walls of tracheids suggesting a gymnospermous wood affinity. Most of the charcoal specimens exhibit rounded edges suggesting an allochthonous origin. Furthermore, fusinite reflectance (1.03–6.61%) of studied charcoal/inertinite fragments suggests that the temperature was in the range of ~305–962°C during charring. This indicates co-occurrence of high-temperature crown fires, together with medium- and low-temperature surface and ground fires, respectively. Our data emphasise the dominance of gymnospermous vegetation during the Permian in India and adds further evidence for the widespread occurrence of wildfires during this period in India and on entire Gondwana as well. [ABSTRACT FROM AUTHOR]

Macroscopic fossil charcoal fragments have been recovered from the borehole AK-19 (at a depth of 120.00 m) drilled at the Astona-Kothurna coal block, Wardha valley coalfield. In general, the occurrence of charcoal in sediments is accepted as a direct indicator for palaeo-wildfires. The charcoal fragments exhibits well preserved homogenized cell walls as well as anatomical details such as uniseriate and biseriate pitting patterns on tracheid walls under Field Emission Scanning Electronic Microscope (FESEM), suggesting a gymnospermous wood affinity of the studied material. The excellent preservation, their large size and almost unabraded edges of charcoal fragments suggest a par-autochthonous origin. These findings add further evidence for the widespread occurrence of such wildfires during the Early Permian not only in India, but on the entire Gondwana continent. [ABSTRACT FROM AUTHOR]

Macroscopic charcoal is recovered from the sub-surface sediments from Bore core SKB-1 which intersected Barren Measure Formation and Raniganj Formation of South Karanpura coalfield. These charcoal particles are widely accepted to be of palaeowildfire products and this study contributes to the Middle and Late Permian wildfire data of Indian peninsula. In the present investigation the charcoal particles are studied using reflected light, transmitted light and Scanning Electron microscopy to document their anatomical structure, morphology and temperature of formation. The inertinite reflectance data reveal that these charcoals were formed at a temperature of 600° C which is evident by the homogenized cell walls as homogenization takes place at temperatures above 500° C. Petrographic analysis reveals high inertinite content and the calculated Gelification Index and Tissue preservation Index suggest that the sediments from which the charcoal particles were retrieved were deposited in a dry forest swamp which was conducive for the forest fire to propagate as the forest litter provided the fuel load. The morphological characters of charcoal were utilized in delineating its taphonomy and it indicates that they are hypautochthonous in nature. [ABSTRACT FROM AUTHOR]

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. • An integrated approach depicting the palaeovegetation and depositional environment • Study resolves the ambiguity regarding the age of studied sediments in this basin • Accumulation of organic matter occurred under dysoxic-oxic conditions • Fossil charcoal indicate occurrence of palaeowildfires in the source area • Macerals group indicate significant contribution of higher plants for peat formation [ABSTRACT FROM AUTHOR]