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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]

A rich Glossopteris dominated plant fossils assemblage is recovered from the Barakar Formation of Lalmatia coal mine, Hura coalfield of Rajmahal Basin, Godda district, Jharkhand, India. The assemblage includes Glossopteris, Gangamopteris and Noeggerathiopsis (leaf forms) along with Vertebraria (root form). There are 4 genera and 14 species of megafossils in the collection, which includes 10 species of Glossopteris, two species of Gangamopteris and one species of Noeggerathiopsis and Vertebraria each. The flora, although similar to that of the Barakar Formation of the Damodar Basin complex, exhibit unique characteristics and is of Artinskian to Kungurian in age. The palynoassemblage recovered in the section reveals the dominance of genus Scheuringipollenites and sub-dominance of Faunipollenites (=Protohaploxypinus) along with Parasaccites, Potonieisporites, Barakarites, Plicatipollenites, Striomonosaccites, Striatopodocarpites, Crescentipollenites, Verticipollenites, Rhizomaspora, Distriatites, Primuspollenites, Striasulcites, Lunatisporites, Guttulapollenites, Platysaccus, Microfoveolatispora, Microbaculispora, Horriditriletes, Tiwariasporis and Weylandites, which demonstrates an early Permian age (Artinskian). The palynoassemblage indicates that the sediments belong to the lower part of the Barakar Formation. Biomarker analysis suggests varying organic matter input during the deposition of the studied sequence. Diterpane compounds and megafossil evidences suggest Glossopteris were the dominant flora along with conifers. Bacterial alteration of the organic matter is inferred from the hopane compounds. The δ13C value of organic matter associated with the carbonaceous shale directly corroborates with the typical δ13C values of the Permian time and is suggestive of warm and humid climatic conditions. [ABSTRACT FROM AUTHOR]

The palynological and palynofacies studies have been undertaken on the sub-surface sediments of borehole AK-19 from Asthona area of the Wardha coalfield, India. The present investigation has revealed the existence of two distinct palynological assemblages, which have been designated as palynoassemblage - I and II respectively. The former, has shown a predominance of monosaccates viz., Parasaccites, Plicatipollenites, Potonieisporites, and Crucisaccites, whereas, the latter is characterized by the dominance of striate bisaccates such as Faunipollenites and subdominance of non-striate bisaccate Scheuringipollenites along with other striate forms such as Striatopodocarpites, Crescentipollenites, and Rhizomaspora. The other genera recorded mainly includes Parasaccites, Indotriradites, and Callumispora, which suggests that primarily herbaceous and the arborescent plants where luxuriantly growing in the forest with the prevalence of hygrophilous and mesophilous environmental conditions. The recovered palynoassemblages are governed mainly by the gymnosperms such as glossopterids, conifers, and cordaites, etc., flourished in near shore areas in riverine, lacustrine conditions as well as in large swamps and marshy habitat with the prevalence of initially cold climatic conditions (Palynoassemblage-I) which later on became temperate (Palynoassemblage-II).The present palynoassemblages have a closer affiliation with the known early Permian palynofloras of other Gondwana basins of India such as Umrer and Kamthi coalfields and Godavari, Damodar, Son-Mahanadi and Satpura basins. It can also be tentatively correlated with the early Permian palynoassemblages ofo South America, Antarctica, Australia, Africa and Salt range of Pakistan. Hence, Artinskian and Kungurian age (early Permian) has been assigned to the studied palynoassemblages respectively.The study of organic matter has revealed three distinct palynofacies (I-III) which are characterized by the dominance of palynomorphs (Palynofacies-I), phytoclasts (Palynofacies-II) and biodegraded organic matter (Palynofacies-III) respectively. Palynofacies-I-III reflects the proximal fresh water settings; oxidizing fluvio-deltaic near shore conditions and distal dysoxic waterlogged settings respectively. Palynofacies-I and II represent the oxidizing conditions while Palynofacies-III represents the reducing conditions. [ABSTRACT FROM AUTHOR]

Palynological and petrological studies have been undertaken on the Gondwana coal and associated lithologies encountered in borehole EBM-2 of East Bokaro coalfield of Damodar Basin, India. The palynological investigation resulted in the recognition of Assemblage-III ( Densipollenites, 27.9 m-214.30 m), Assemblage-II ( Striatopodocarpites + Faunipollenites, 225.00 m-297.60 m) and Assemblage-I ( Faunipollenites + Scheuringipollenites, 307.00m-433.00 m). Lithofacies study was also done for better understanding of the preservation and abundance/paucity of the spores and pollen in different lithologies as the current borehole has significant thickness of mudstones, shales and siltstone. Palynofacies study and Petrographical studies of coal samples encountered in the borehole were used to determine the depositional environment of the coal precursor peat swamp. Palynological data has revealed the presence of younger Raniganj palynoflora between 27.00-214.30 m depth that is lithologically defined as Barren Measures Formation. This spore pollen study has proved that these sediments were deposited during late early Permian to late Permian period. Further the maceral analysis of organic sediments as well as the Thermal Alteration Index (TAI) has revealed that the coaly shale at 336.5 m depth has hydrocarbon generation potential. [ABSTRACT FROM AUTHOR]

The present work deals with the palaeoenvironment and depositional setting of the subsurface sediments from bore hole RT-4 of Tamra block from Raniganj coalfield of Damodar Basin, India. Nineteen shale samples were subjected to palynological and coal petrographical analyses. On the basis of botanical affinity between the miospores and the parent plants as well as the different plant groups, each coal plant assemblage was determined. The dominance of bisaccates such as Scheuringipollenites, Faunipollenites (= Protohaploxypinus), Striatopodocarpites and presence of monosaccates such as Densipollenites, Parasaccites reflect a peat forming community composed mainly of gymnosperms. Subordinate trilete spores derived from filicopsids ( Cyclogranisporites, Horriditriletes, Brevitirletes, Callumispora, Microbaculsispora, Microfoveolatispora, Cyclobaculisporites), lycopsids ( Indotriradites, Gondispoirtes and Didecitriletes) and sphenopsids ( Laevigatosporites ) are less abundant occurring in variable proportions reflecting a hypautocthonous taphocenose. Presence of Botryococccus algae has been recorded. Palynofacies and petrographic analyses suggest deposition in open mires in a Limnic to limno-telmatic conditions with intermittent flooding of the site. [ABSTRACT FROM AUTHOR]

Petrographic analysis of the coals from bore core EBM-1 of East Bokaro Coalfield revealed characteristic changes as a result of thermal alteration by an intrusive body. The enhancement of 'rank' (increase in the VR% values) is observed in the heat affected coal in the lower part of the bore core. The vitrinite in the coal at a depth of 984.95 m showed devolatilization vacuoles and initiation of mosaic structure due to heat alteration, dessication cracks and micropores. Meta-liptinite having reflectance value higher (1.67%) than that of the host vitrinite (1.09% - 1.36%) was also recorded. Bi-reflectance values of the un-altered coals were normal in the range of 0.06% - 0.09% where as the altered coal at a depth of 984.95 m showed an abnormal increase in the values (0.23%). Presence of secondary injected mineral matter and char particles further indicate the effect of thermal alteration. Palynological investigation of both altered and un-altered coal reveals that the palynomorphs recovered from the altered coal are dark and opaque due to the charring effect while the palynomorphs from un-altered coals exhibit a clear internal structure and can be easily identified. [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]