This paper results from a taxonomic study of platyspermic seeds from taphofloristic assemblage of... more This paper results from a taxonomic study of platyspermic seeds from taphofloristic assemblage of the "Toca do indio Ranch", belonging to the upper pOliion of the Itarare Subgroup, Municipality of Cerquilho (SP) and a revision of material collected by Millan (1977) from the same area which is deposited in the National Museum of Rio de Janeiro. The assemblage comprises the Transitional Taphoflora (A-B) or the Gangamopleris-Rubidgea-Slephanophylliles association from the type-locality of Northeastern Parana Basin. This taphoflora is Early Permian (Asselian-Early Sakmarian) in age and records the beginning of the colonization of the Parana Basin by the proto-glossopterid and gangamopterid elements of the Glossopteris flora. It is, probably, correlated to the Argentinean "Lubeckense A" Floristic Stage or even a little older. The platyspennic seeds are assigned to the genera Salllaropsis and Cordaicarp/ls. The assemblage is diversified and includes the taxa Cordaicarpus brasilian/ls n. sp., Samaropsis dolianitii Millan, S. rigbyi Millan, S. lielensis Millan, S cerq/lilhensis (Millan) comb. nov., S moreirana (White) Millan, S. goraiensis Surange & Lele, S. rugata sp. nov. and S rohnii sp.nov. The record of S moreiran({ (White) Millan in the present study is the oldest from the Parana Basin and S goraiensis Surange & Lele is recognized for the first time outside India. The wide variety of detached seeds reflect the diversification of the gymnospenns in this assemblage, putatively related to the last interglacial event of the Lower Gondwana glaciation in the Parana Basin. Biostratigraphic con'elati-:>n based on seeds is not possible due to apparent endemic nature of the assemblage and further work in this field is required.
Tewari, R., Pandita, S.K., Agnihotri, D., Pillai, S.S.K. &amp... more Tewari, R., Pandita, S.K., Agnihotri, D., Pillai, S.S.K. & Bernardes-De-Oliveira, M.E.C., iFirst article. An Early Permian Glossopteris flora from the Umrer Coalfield, Wardha Basin, Maharashtra, India. Alcheringa, 1–18. ISSN 0311-5518.A rich and well-preserved Glossopteris-dominated plant fossil assemblage is described from the Barakar Formation of the Makardhokra and Umrer open-cast projects, Umrer Coalfield, Nagpur District, Wardha Basin, Maharashtra, India. The assemblage
Well preserved palynomorphs from the Barakar Formation of Dhanpuri Open Cast Mine, Sohagpur Coalf... more Well preserved palynomorphs from the Barakar Formation of Dhanpuri Open Cast Mine, Sohagpur Coalfield, Shahdol District, Madhya Pradesh are reported for the first time. The palynomorphs include megaspores and spores/pollen grains. Dispersed megaspores are represented by 6 genera and 13 species comprising Banksisporites indicus, B. utkalensis, Banksisporites sp., Barakarella shuklae, Barakarella sp., Biharisporites sp. Bokarosporites rotundus, Bokarosporites sp., Jhariatriletes baculosus, Jhariatriletes sp., Talchirella flavata, T. trivedii and Talchirella sp. The microspore assemblage shows dominance of monosaccate pollen grains namely Parasaccites obscures, P. korbaensis and Plicatipollenites indicus, along with sub-dominance of non-striate bisaccate taxa Scheuringipollenites barakarensis and S. maximus. Other palynomorphs include trilete Callumispora barakarensis, striate bisaccate pollen grains Faunipollenites sp. and Striatopodocarpites multistriatus, non striate bisaccate genera Ibisporites diplosaccus and Platysaccus ovatus, along with Tiwariasporis gondwanensis and Vitreisporites sp.
Well preserved plant fossil assemblage recorded for the first time from the Barakar Formation of ... more Well preserved plant fossil assemblage recorded for the first time from the Barakar Formation of Sharda Open Cast Mine, Sohagpur Coalfield, Shahdol District, Madhya Pradesh is documented in this study. The assemblage comprises the orders Equisetales, Glossopteridales and Cordaitales. Equisetales is represented by unidentifiable leafless equisetalean axes bearing nodes and internodes, Glossopteridales comprises one species of Gangamopteris (Gangamopteris intermedia) and seven species of Glossopteris (Glossopteris communis, G. gigas, G. giridihensis, G. indica, G. longicaulis, G. spatulata and Glossopteris sp.), and Cordaitales is known by one species of Noeggerathiopsis (Noeggerathiopsis hislopii). The floral assemblage is broadly comparable with those described previously from the Barakar Formation of Damodar, Mahanadi, Wardha, Godavari, Rajmahal and Satpura Gondwana basins of India. Since the known records of plant mega fossils from the Barakar Formation of Sohagpur Coalfield are m...
A rich megaspore assemblage has been recorded from the Early Permian Barakar Formation of Umrer C... more A rich megaspore assemblage has been recorded from the Early Permian Barakar Formation of Umrer Coalfield, Wardha Basin. The assemblage is represented by nine genera and thirteen species. Bokarospori/es rOlUndus, Banksispori/es indicus, B. utkalensis, Duospori/es congoensis, D. irregularis, Duospori/es sp., Barakarella pan/ii, Talchirella /rivedii, Jharia/rile/es baculosus, two new species-Biharispori/es umrerensis and B. waigaoensis besides the taxa Lagenoispori/es sp. and Se/osispori/es hirsutus. The last two are reported for the first time from India Preponderance of trilete and gulate megaspores indicates a dominance of Cryptogams and an association of gulate forms, in particular. suggests lycopsid affinity. The assemblage indicates prevalence of marshy and humid environmental conditions of deposition.
The sub–surface samples of bore core NP–75 drilled near Nand Village, a part of Nand–Besur Block ... more The sub–surface samples of bore core NP–75 drilled near Nand Village, a part of Nand–Besur Block of Bandar Coalfield, Wardha Basin, Maharashtra have yielded palynomorphs which include spores/pollen grains and megaspores. The pollen assemblage shows the dominance of the genus Scheuringipollenites and sub–dominance of Faunipollenites (=Protohaploxypinus) along with Caheniasaccites, Plicatipollenites, Potonieisporites, Barakarites, Arcuatipollenites, Striatopodocarpites, etc. Megaspores are represented by three genera and nine species comprising Bokarosporites rotundus, Bokarosporites sp., Jhariatriletes filiformis, Singhisporites baculatus, S. indica, S. nautiyalii, S. radialis, S. surangei and Singhisporites sp. The palynomorph assemblage indicates an early Permian age equivalent to the lower Barakar Formation.
Major, trace and rare earth element (REE) geochemistry has been carried out in this paper to char... more Major, trace and rare earth element (REE) geochemistry has been carried out in this paper to characterize source–rock weathering and climatic variability of the late Permian Weller Formation and the late Triassic Lashly Formation of Gondwana sequences which have yielded rich record of plant mega–and micro fossils associated with coal beds in post–glacial conditions in Allan Hills of South Victoria Land, Antarctica. The geochemistry suggests dominantly a felsic provenance with a volcanogenic input and role of weathering and hydrothermal alteration. The palaeoclimatic interpretation derived from geochemical analysis indicates warm, temperate and humid conditions during the late Permian, and warm and humid conditions during the late Triassic.
Scutum-type female Glossopterid fructification is described from the Raniganj Formation (Upper Pe... more Scutum-type female Glossopterid fructification is described from the Raniganj Formation (Upper Permian) of Bhatdih and Murulidih collieries of Jharia Coalfield, Bihar, India. Statistical analysis of shape, apex, base and total number of scars on the receptacle show that majority of specimens are lanceolate in shape and have acute apices. The base is stalked with wide marginal border and usually rounded where margins are absent. Total number of Scars ranges between 20 and 45. The study shows that a number of multiovulate fructification genera, viz., Plumsteadia, Hirsutum, Plumsteadiostrobus, Venustostrobus and jambadostrobus,which have been differentiated on the basis of presence or absence of marginal wings and cuticular features, in all possibilities are related to each other and quite likely represent the developmental or maturation stages of a single type glossopterid fructification.
Plant megafossils recorded from the Kamthi Formation of India have been assessed in the present c... more Plant megafossils recorded from the Kamthi Formation of India have been assessed in the present communication. The formation is mainly exposed in the Mahanadi, Godavari and Wardha basins and has been critically analysed on the basis of its megafloral and palynological contents, and the lithological aspects by earlier workers who variously assigned its age as late Permian, early and late Triassic. An endeavour has been made here to compile all the known plant fossil records from the Kamthi Formation for better understanding of its floral and biostratigraphical significance. Known records of the plant megafossils from the Kamthi Formation reveal dominance of the Glossopteris flora and paucity of the Dicroidium floral elements suggesting a transition between late Permian and early Triassic.
Scanning electron microscopy of cuticles of glossopteris fructification (Sculum type) recovered f... more Scanning electron microscopy of cuticles of glossopteris fructification (Sculum type) recovered from the Upper Permian sequence of Jharia coalfield demonstrates damaged cellular tissue and bacteria like structures. Occurrence of bacteria over the marred surface of seed cuticle possessing plaque/pit suggests role of micro-organisms in biodegradation of Glossopteris flora.
A 1300 m thick sedimentary sequence in borehole SNB–1 around Jaisinghnagar area in the western pa... more A 1300 m thick sedimentary sequence in borehole SNB–1 around Jaisinghnagar area in the western part of the South Rewa Basin has been lithologically designated as the Pali Formation. However, palynological investigation reveals presence of three distinct palynoassemblage zones belonging to late Permian, early and late Triassic ages in ascending order. Palynoassemblage I (Striatopodocarpites magnificus–Crescentipollenites fuscus) recorded between a depth of 1213.40–1164.10 m showing dominance of striate bisaccate pollen taxa chiefly―Striatopodocarpites ovatus, Faunipollenites varius and Crescentipollenites fuscus in association with Alisporites ovalis, Lunatisporites pellucidus, Densipollenites indicus and Lahirites rarus is late Permian (Raniganj) in age. Palynoassemblage II (Lundbladispora densispinosa–Densoisporites playfordii) recorded between a depth of 1054.30–956.00 m and showing dominance of cavate/cingulate spores, like Lundbladispora microconata, Densoisporites complicatus a...
The Pennsylvanian strata of the Itararé Group are present on the northeastern border of the Paran... more The Pennsylvanian strata of the Itararé Group are present on the northeastern border of the Paraná Basin, i.e. northern part of Paraná State towards north of São Paulo. The Pennsylvanian lycopods of the Itararé Group are represented by diverse megafossils, megaspores and microspores. The present study deals with the lycopsid megafossils from the third interglacial level of the paleofloristic succession of the Itararé Group in the northeastern border of the Paraná Basin, i.e. Paranocladus-Ginkgophyllum-Brasilodendron association (PGB as.) recovered from its type locality Volpe ranch, in Monte Mor municipality, SP. The megafossils belong to the taxa Bumbudendron millani, Bumbudendron cf. B. paganzianum, Brasilodendron pedroanum, Brasilodendron sp., Leptophloeum cf. L. sanctae-helenae, and Cyclodendron sp. The diversity and abundance of the megafossils (sometimes forming coal beds in a glacial context) indicates climatic ameliorations of an interglacial phase of the “time Itararé”. The...
Early Permian megaspores are reported for the first time from the Barakar Formation of Index Seam... more Early Permian megaspores are reported for the first time from the Barakar Formation of Index Seam, Goutham Khani Open Cast Mine, Kothagudem Area, Godavari Graben, Telangana, India. The megaspore assemblage includes three genera and ten species, namely Biharisporites spinosus, Biharisporites sp. A (in Tewari et al., 2009), Biharisporites sp., Jhariatriletes filiformis, Jhariatriletes sp., Singhisporites indica, S. nautiyalii, S. radialis, S. surangei and Singhisporites sp. Besides adding to the existing knowledge of megaspores from the Godavari Graben, the comparison of megaspores from the Goutham Khani Open Cast Mine with those of the other Indian Lower Gondwana basins, namely Damodar, Satpura, Wardha, South Rewa and other areas of the Godavari Graben reveals that majority of these differ in the presence of dense ornamentations on their exosporia. The previous records of megaspores from the late Permian of the Godavari Graben show dense spinate exosporia. Presence of such dense dive...
There are three major coal seams in the Raniganj Formation of Jharia Coalfield, viz., Mahuda, Bhu... more There are three major coal seams in the Raniganj Formation of Jharia Coalfield, viz., Mahuda, Bhurungia and Lohpiti, in ascending order. The main constituents of the plant fossil assemblage from the roof shale of Lohpiti Seam, thal underlies the Lohpiti Sandstone Member, are the leaf Glossopteris shailae, the Stem Araucarioxylon kumarpurensis and the megaspore Noniasporites harrisii. A similar fossil assemblage has earlier been reported from the roof shales of Kajora Seam that underlies the Kumarpur Sandstone Member of Raniganj Formation in Raniganj Coalfield. The correlatability of Lohpiti Sandstone Member with Kumarpur Sandstone Member is established.
A survey of megaspore studies from Penman ofRamagundam, Chelpur, Mailaram, Rampuram, Gundala and ... more A survey of megaspore studies from Penman ofRamagundam, Chelpur, Mailaram, Rampuram, Gundala and Kachinapalli areas of Godavari Graben, Andhra Pradesh indicates their qualitative and quantitative richness during the Late Permian. Out of seventy nine megaspore taxa recorded from Indian Lower Gondwana, twenty three are represented in this graben. Presence of Biharisporites sparsus in the Raniganj Fonnation ofKachinapalli area is palticularly significant because it was previously recorded from Triassic and thus indicates an early appearance ofTriassic taxon in Godavari Graben in Late Pelmian. Additionally, the survey also records a higher (eighteen) number of megaspore taxa in the Raniganj Fonnation. A distinct evolutionary trend is observed since exosporia of megaspores from the Barakar Fomlation are simple and those of the Raniganj Formation are complex and more diversified.
The rise of the Himalayas governed the Indian Summer Monsoon in Karewa basin during Plio-Pleistoc... more The rise of the Himalayas governed the Indian Summer Monsoon in Karewa basin during Plio-Pleistocene. A palynological study is presented to delineate the climate-vegetation relationship using an 8.5-m thick fluvio-lacustrine sequence of the Hirpur Formation (2.4–2.1 Ma). Our results suggest that the sediment sequence is mainly comprised of two units, namely, Unit 1 and Unit 2. Unit 1 shows the dominance of sub-tropical to broad-leaf temperate vegetation when mean annual temperature (MAT) was ~17°C and mean annual precipitation (MAP) was 1025 mm. The subsequent increase in sand followed by a thin lignite layer with Trapa megafossil (fruits) demarcates fluvial adjustments, suggesting a low altitude fluvio-lacustrine ecosystem. Conversely, Unit 2 shows a decline in rainforest pollen with a steady increase in conifers. The abrupt dominance of diatom species Tetracyclus lacustris and related species with MAT and MAP reducing to 10°C and 770 mm reveal a colder climate with the lacustrine ecosystem. This change of tropical to cool temperate vegetation could be attributed to the altitudinal rise of the Pir Panjal Mountains and consequent obstruction of the south-west monsoon, which resulted in lower precipitation and temperature during ~2.4–2.1 Ma. Hence, the relic tropical flora of Palaeogene/Neogene transformed to Himalayan temperate flora sometime ~2.1 Ma. Climate–vegetation relationship is established through a palynological record. Unit 1 comprises subtropical to broad-leaf temperate vegetation with warmer mean annual temperature and higher mean annual precipitation. Unit 2 comprises colder diatom species and is following cooler mean annual temperature and lower mean annual precipitation. A shift of tropical to cool temperate vegetation is related to the rise of the Pir Panjal Mountains, obstructing monsoon. Climate–vegetation relationship is established through a palynological record. Unit 1 comprises subtropical to broad-leaf temperate vegetation with warmer mean annual temperature and higher mean annual precipitation. Unit 2 comprises colder diatom species and is following cooler mean annual temperature and lower mean annual precipitation. A shift of tropical to cool temperate vegetation is related to the rise of the Pir Panjal Mountains, obstructing monsoon.
First palynological data, supplemented by detrital zircon U-Pb ages, from the Fenestella Shale Fo... more First palynological data, supplemented by detrital zircon U-Pb ages, from the Fenestella Shale Formation near the Gund Village in the Banihal area of Jammu and Kashmir State, India, provide new insights into the floristic evolution of Gondwana during the Late Palaeozoic, especially in India, from where the Carboniferous-Permian macro-and microfloral records are impoverished. We also present a first approach to the palynological correlation of the Carboniferous-Permian palynoassemblages described from the various Gondwana countries. 2 The palynomorphs from the Fenestella Shale Formation are fairly well preserved and diversified and include 11 genera and 18 species. While the trilete spores and striate bisaccate pollen grains are scarce, monosaccate pollen taxa mainly-Parasaccites, Plicatipollenites and Potonieisporites are dominant. The assemblage is most similar to the Parasaccites korbaensis palynozone of the Lower Gondwana basins of the Indian peninsula and the Stage 2 palynozone of the late Carboniferous of east Australia. Besides, it is comparable with the known Carboniferous assemblages of Pakistan, Yemen and South America; Carboniferous-early Permian assemblages of South Africa and Permian assemblages of Antarctica. The sediment source of the siliciclastic shelf and delta deposits intercalated in the Fenestella Shale Formation is a hinterland in which Precambrian rocks dominantly were exposed and the Th-U ratios of detrital zircons suggest, that most rocks exposed on the erosion level in the hinterland had a felsic composition. The youngest U-Pb zircon age of the investigated fossiliferous strata is 329 ± 16 Ma (late Visean to early Serpukhovian), providing a maximum age of deposition of the studied succession. Based on the affinities of the palynofloral assemblage and earlier palaeontological records, a warm, temperate and arid climate has been inferred for the Fenestella Shale Formation.
Research highlights Geochemistry and petrographical studies from the Guryul Ravine section, Jam... more Research highlights Geochemistry and petrographical studies from the Guryul Ravine section, Jammu and Kashmir, India are carried out to decipher the oceanic redox conditions at Permian-Triassic boundary (PTB) in the area. Redox sensitive elements like Ni, Co, Cr, V, U at PTB and negative Ce anamoly in the early Triassic sediments of Khunamuh Formation indicate reducing environmental conditions. The prolonged reducing conditions were probably the source of water anoxia, which may be one of the causes for the PTB mass extinction. Ternary A-CN-K plot shows moderate weathering at PTB (CIA 72), whereas, below the Late Permian Event Horizon (CIA 60), physical weathering is more prominent.
This paper results from a taxonomic study of platyspermic seeds from taphofloristic assemblage of... more This paper results from a taxonomic study of platyspermic seeds from taphofloristic assemblage of the "Toca do indio Ranch", belonging to the upper pOliion of the Itarare Subgroup, Municipality of Cerquilho (SP) and a revision of material collected by Millan (1977) from the same area which is deposited in the National Museum of Rio de Janeiro. The assemblage comprises the Transitional Taphoflora (A-B) or the Gangamopleris-Rubidgea-Slephanophylliles association from the type-locality of Northeastern Parana Basin. This taphoflora is Early Permian (Asselian-Early Sakmarian) in age and records the beginning of the colonization of the Parana Basin by the proto-glossopterid and gangamopterid elements of the Glossopteris flora. It is, probably, correlated to the Argentinean "Lubeckense A" Floristic Stage or even a little older. The platyspennic seeds are assigned to the genera Salllaropsis and Cordaicarp/ls. The assemblage is diversified and includes the taxa Cordaicarpus brasilian/ls n. sp., Samaropsis dolianitii Millan, S. rigbyi Millan, S. lielensis Millan, S cerq/lilhensis (Millan) comb. nov., S moreirana (White) Millan, S. goraiensis Surange & Lele, S. rugata sp. nov. and S rohnii sp.nov. The record of S moreiran({ (White) Millan in the present study is the oldest from the Parana Basin and S goraiensis Surange & Lele is recognized for the first time outside India. The wide variety of detached seeds reflect the diversification of the gymnospenns in this assemblage, putatively related to the last interglacial event of the Lower Gondwana glaciation in the Parana Basin. Biostratigraphic con'elati-:>n based on seeds is not possible due to apparent endemic nature of the assemblage and further work in this field is required.
Tewari, R., Pandita, S.K., Agnihotri, D., Pillai, S.S.K. &amp... more Tewari, R., Pandita, S.K., Agnihotri, D., Pillai, S.S.K. & Bernardes-De-Oliveira, M.E.C., iFirst article. An Early Permian Glossopteris flora from the Umrer Coalfield, Wardha Basin, Maharashtra, India. Alcheringa, 1–18. ISSN 0311-5518.A rich and well-preserved Glossopteris-dominated plant fossil assemblage is described from the Barakar Formation of the Makardhokra and Umrer open-cast projects, Umrer Coalfield, Nagpur District, Wardha Basin, Maharashtra, India. The assemblage
Well preserved palynomorphs from the Barakar Formation of Dhanpuri Open Cast Mine, Sohagpur Coalf... more Well preserved palynomorphs from the Barakar Formation of Dhanpuri Open Cast Mine, Sohagpur Coalfield, Shahdol District, Madhya Pradesh are reported for the first time. The palynomorphs include megaspores and spores/pollen grains. Dispersed megaspores are represented by 6 genera and 13 species comprising Banksisporites indicus, B. utkalensis, Banksisporites sp., Barakarella shuklae, Barakarella sp., Biharisporites sp. Bokarosporites rotundus, Bokarosporites sp., Jhariatriletes baculosus, Jhariatriletes sp., Talchirella flavata, T. trivedii and Talchirella sp. The microspore assemblage shows dominance of monosaccate pollen grains namely Parasaccites obscures, P. korbaensis and Plicatipollenites indicus, along with sub-dominance of non-striate bisaccate taxa Scheuringipollenites barakarensis and S. maximus. Other palynomorphs include trilete Callumispora barakarensis, striate bisaccate pollen grains Faunipollenites sp. and Striatopodocarpites multistriatus, non striate bisaccate genera Ibisporites diplosaccus and Platysaccus ovatus, along with Tiwariasporis gondwanensis and Vitreisporites sp.
Well preserved plant fossil assemblage recorded for the first time from the Barakar Formation of ... more Well preserved plant fossil assemblage recorded for the first time from the Barakar Formation of Sharda Open Cast Mine, Sohagpur Coalfield, Shahdol District, Madhya Pradesh is documented in this study. The assemblage comprises the orders Equisetales, Glossopteridales and Cordaitales. Equisetales is represented by unidentifiable leafless equisetalean axes bearing nodes and internodes, Glossopteridales comprises one species of Gangamopteris (Gangamopteris intermedia) and seven species of Glossopteris (Glossopteris communis, G. gigas, G. giridihensis, G. indica, G. longicaulis, G. spatulata and Glossopteris sp.), and Cordaitales is known by one species of Noeggerathiopsis (Noeggerathiopsis hislopii). The floral assemblage is broadly comparable with those described previously from the Barakar Formation of Damodar, Mahanadi, Wardha, Godavari, Rajmahal and Satpura Gondwana basins of India. Since the known records of plant mega fossils from the Barakar Formation of Sohagpur Coalfield are m...
A rich megaspore assemblage has been recorded from the Early Permian Barakar Formation of Umrer C... more A rich megaspore assemblage has been recorded from the Early Permian Barakar Formation of Umrer Coalfield, Wardha Basin. The assemblage is represented by nine genera and thirteen species. Bokarospori/es rOlUndus, Banksispori/es indicus, B. utkalensis, Duospori/es congoensis, D. irregularis, Duospori/es sp., Barakarella pan/ii, Talchirella /rivedii, Jharia/rile/es baculosus, two new species-Biharispori/es umrerensis and B. waigaoensis besides the taxa Lagenoispori/es sp. and Se/osispori/es hirsutus. The last two are reported for the first time from India Preponderance of trilete and gulate megaspores indicates a dominance of Cryptogams and an association of gulate forms, in particular. suggests lycopsid affinity. The assemblage indicates prevalence of marshy and humid environmental conditions of deposition.
The sub–surface samples of bore core NP–75 drilled near Nand Village, a part of Nand–Besur Block ... more The sub–surface samples of bore core NP–75 drilled near Nand Village, a part of Nand–Besur Block of Bandar Coalfield, Wardha Basin, Maharashtra have yielded palynomorphs which include spores/pollen grains and megaspores. The pollen assemblage shows the dominance of the genus Scheuringipollenites and sub–dominance of Faunipollenites (=Protohaploxypinus) along with Caheniasaccites, Plicatipollenites, Potonieisporites, Barakarites, Arcuatipollenites, Striatopodocarpites, etc. Megaspores are represented by three genera and nine species comprising Bokarosporites rotundus, Bokarosporites sp., Jhariatriletes filiformis, Singhisporites baculatus, S. indica, S. nautiyalii, S. radialis, S. surangei and Singhisporites sp. The palynomorph assemblage indicates an early Permian age equivalent to the lower Barakar Formation.
Major, trace and rare earth element (REE) geochemistry has been carried out in this paper to char... more Major, trace and rare earth element (REE) geochemistry has been carried out in this paper to characterize source–rock weathering and climatic variability of the late Permian Weller Formation and the late Triassic Lashly Formation of Gondwana sequences which have yielded rich record of plant mega–and micro fossils associated with coal beds in post–glacial conditions in Allan Hills of South Victoria Land, Antarctica. The geochemistry suggests dominantly a felsic provenance with a volcanogenic input and role of weathering and hydrothermal alteration. The palaeoclimatic interpretation derived from geochemical analysis indicates warm, temperate and humid conditions during the late Permian, and warm and humid conditions during the late Triassic.
Scutum-type female Glossopterid fructification is described from the Raniganj Formation (Upper Pe... more Scutum-type female Glossopterid fructification is described from the Raniganj Formation (Upper Permian) of Bhatdih and Murulidih collieries of Jharia Coalfield, Bihar, India. Statistical analysis of shape, apex, base and total number of scars on the receptacle show that majority of specimens are lanceolate in shape and have acute apices. The base is stalked with wide marginal border and usually rounded where margins are absent. Total number of Scars ranges between 20 and 45. The study shows that a number of multiovulate fructification genera, viz., Plumsteadia, Hirsutum, Plumsteadiostrobus, Venustostrobus and jambadostrobus,which have been differentiated on the basis of presence or absence of marginal wings and cuticular features, in all possibilities are related to each other and quite likely represent the developmental or maturation stages of a single type glossopterid fructification.
Plant megafossils recorded from the Kamthi Formation of India have been assessed in the present c... more Plant megafossils recorded from the Kamthi Formation of India have been assessed in the present communication. The formation is mainly exposed in the Mahanadi, Godavari and Wardha basins and has been critically analysed on the basis of its megafloral and palynological contents, and the lithological aspects by earlier workers who variously assigned its age as late Permian, early and late Triassic. An endeavour has been made here to compile all the known plant fossil records from the Kamthi Formation for better understanding of its floral and biostratigraphical significance. Known records of the plant megafossils from the Kamthi Formation reveal dominance of the Glossopteris flora and paucity of the Dicroidium floral elements suggesting a transition between late Permian and early Triassic.
Scanning electron microscopy of cuticles of glossopteris fructification (Sculum type) recovered f... more Scanning electron microscopy of cuticles of glossopteris fructification (Sculum type) recovered from the Upper Permian sequence of Jharia coalfield demonstrates damaged cellular tissue and bacteria like structures. Occurrence of bacteria over the marred surface of seed cuticle possessing plaque/pit suggests role of micro-organisms in biodegradation of Glossopteris flora.
A 1300 m thick sedimentary sequence in borehole SNB–1 around Jaisinghnagar area in the western pa... more A 1300 m thick sedimentary sequence in borehole SNB–1 around Jaisinghnagar area in the western part of the South Rewa Basin has been lithologically designated as the Pali Formation. However, palynological investigation reveals presence of three distinct palynoassemblage zones belonging to late Permian, early and late Triassic ages in ascending order. Palynoassemblage I (Striatopodocarpites magnificus–Crescentipollenites fuscus) recorded between a depth of 1213.40–1164.10 m showing dominance of striate bisaccate pollen taxa chiefly―Striatopodocarpites ovatus, Faunipollenites varius and Crescentipollenites fuscus in association with Alisporites ovalis, Lunatisporites pellucidus, Densipollenites indicus and Lahirites rarus is late Permian (Raniganj) in age. Palynoassemblage II (Lundbladispora densispinosa–Densoisporites playfordii) recorded between a depth of 1054.30–956.00 m and showing dominance of cavate/cingulate spores, like Lundbladispora microconata, Densoisporites complicatus a...
The Pennsylvanian strata of the Itararé Group are present on the northeastern border of the Paran... more The Pennsylvanian strata of the Itararé Group are present on the northeastern border of the Paraná Basin, i.e. northern part of Paraná State towards north of São Paulo. The Pennsylvanian lycopods of the Itararé Group are represented by diverse megafossils, megaspores and microspores. The present study deals with the lycopsid megafossils from the third interglacial level of the paleofloristic succession of the Itararé Group in the northeastern border of the Paraná Basin, i.e. Paranocladus-Ginkgophyllum-Brasilodendron association (PGB as.) recovered from its type locality Volpe ranch, in Monte Mor municipality, SP. The megafossils belong to the taxa Bumbudendron millani, Bumbudendron cf. B. paganzianum, Brasilodendron pedroanum, Brasilodendron sp., Leptophloeum cf. L. sanctae-helenae, and Cyclodendron sp. The diversity and abundance of the megafossils (sometimes forming coal beds in a glacial context) indicates climatic ameliorations of an interglacial phase of the “time Itararé”. The...
Early Permian megaspores are reported for the first time from the Barakar Formation of Index Seam... more Early Permian megaspores are reported for the first time from the Barakar Formation of Index Seam, Goutham Khani Open Cast Mine, Kothagudem Area, Godavari Graben, Telangana, India. The megaspore assemblage includes three genera and ten species, namely Biharisporites spinosus, Biharisporites sp. A (in Tewari et al., 2009), Biharisporites sp., Jhariatriletes filiformis, Jhariatriletes sp., Singhisporites indica, S. nautiyalii, S. radialis, S. surangei and Singhisporites sp. Besides adding to the existing knowledge of megaspores from the Godavari Graben, the comparison of megaspores from the Goutham Khani Open Cast Mine with those of the other Indian Lower Gondwana basins, namely Damodar, Satpura, Wardha, South Rewa and other areas of the Godavari Graben reveals that majority of these differ in the presence of dense ornamentations on their exosporia. The previous records of megaspores from the late Permian of the Godavari Graben show dense spinate exosporia. Presence of such dense dive...
There are three major coal seams in the Raniganj Formation of Jharia Coalfield, viz., Mahuda, Bhu... more There are three major coal seams in the Raniganj Formation of Jharia Coalfield, viz., Mahuda, Bhurungia and Lohpiti, in ascending order. The main constituents of the plant fossil assemblage from the roof shale of Lohpiti Seam, thal underlies the Lohpiti Sandstone Member, are the leaf Glossopteris shailae, the Stem Araucarioxylon kumarpurensis and the megaspore Noniasporites harrisii. A similar fossil assemblage has earlier been reported from the roof shales of Kajora Seam that underlies the Kumarpur Sandstone Member of Raniganj Formation in Raniganj Coalfield. The correlatability of Lohpiti Sandstone Member with Kumarpur Sandstone Member is established.
A survey of megaspore studies from Penman ofRamagundam, Chelpur, Mailaram, Rampuram, Gundala and ... more A survey of megaspore studies from Penman ofRamagundam, Chelpur, Mailaram, Rampuram, Gundala and Kachinapalli areas of Godavari Graben, Andhra Pradesh indicates their qualitative and quantitative richness during the Late Permian. Out of seventy nine megaspore taxa recorded from Indian Lower Gondwana, twenty three are represented in this graben. Presence of Biharisporites sparsus in the Raniganj Fonnation ofKachinapalli area is palticularly significant because it was previously recorded from Triassic and thus indicates an early appearance ofTriassic taxon in Godavari Graben in Late Pelmian. Additionally, the survey also records a higher (eighteen) number of megaspore taxa in the Raniganj Fonnation. A distinct evolutionary trend is observed since exosporia of megaspores from the Barakar Fomlation are simple and those of the Raniganj Formation are complex and more diversified.
The rise of the Himalayas governed the Indian Summer Monsoon in Karewa basin during Plio-Pleistoc... more The rise of the Himalayas governed the Indian Summer Monsoon in Karewa basin during Plio-Pleistocene. A palynological study is presented to delineate the climate-vegetation relationship using an 8.5-m thick fluvio-lacustrine sequence of the Hirpur Formation (2.4–2.1 Ma). Our results suggest that the sediment sequence is mainly comprised of two units, namely, Unit 1 and Unit 2. Unit 1 shows the dominance of sub-tropical to broad-leaf temperate vegetation when mean annual temperature (MAT) was ~17°C and mean annual precipitation (MAP) was 1025 mm. The subsequent increase in sand followed by a thin lignite layer with Trapa megafossil (fruits) demarcates fluvial adjustments, suggesting a low altitude fluvio-lacustrine ecosystem. Conversely, Unit 2 shows a decline in rainforest pollen with a steady increase in conifers. The abrupt dominance of diatom species Tetracyclus lacustris and related species with MAT and MAP reducing to 10°C and 770 mm reveal a colder climate with the lacustrine ecosystem. This change of tropical to cool temperate vegetation could be attributed to the altitudinal rise of the Pir Panjal Mountains and consequent obstruction of the south-west monsoon, which resulted in lower precipitation and temperature during ~2.4–2.1 Ma. Hence, the relic tropical flora of Palaeogene/Neogene transformed to Himalayan temperate flora sometime ~2.1 Ma. Climate–vegetation relationship is established through a palynological record. Unit 1 comprises subtropical to broad-leaf temperate vegetation with warmer mean annual temperature and higher mean annual precipitation. Unit 2 comprises colder diatom species and is following cooler mean annual temperature and lower mean annual precipitation. A shift of tropical to cool temperate vegetation is related to the rise of the Pir Panjal Mountains, obstructing monsoon. Climate–vegetation relationship is established through a palynological record. Unit 1 comprises subtropical to broad-leaf temperate vegetation with warmer mean annual temperature and higher mean annual precipitation. Unit 2 comprises colder diatom species and is following cooler mean annual temperature and lower mean annual precipitation. A shift of tropical to cool temperate vegetation is related to the rise of the Pir Panjal Mountains, obstructing monsoon.
First palynological data, supplemented by detrital zircon U-Pb ages, from the Fenestella Shale Fo... more First palynological data, supplemented by detrital zircon U-Pb ages, from the Fenestella Shale Formation near the Gund Village in the Banihal area of Jammu and Kashmir State, India, provide new insights into the floristic evolution of Gondwana during the Late Palaeozoic, especially in India, from where the Carboniferous-Permian macro-and microfloral records are impoverished. We also present a first approach to the palynological correlation of the Carboniferous-Permian palynoassemblages described from the various Gondwana countries. 2 The palynomorphs from the Fenestella Shale Formation are fairly well preserved and diversified and include 11 genera and 18 species. While the trilete spores and striate bisaccate pollen grains are scarce, monosaccate pollen taxa mainly-Parasaccites, Plicatipollenites and Potonieisporites are dominant. The assemblage is most similar to the Parasaccites korbaensis palynozone of the Lower Gondwana basins of the Indian peninsula and the Stage 2 palynozone of the late Carboniferous of east Australia. Besides, it is comparable with the known Carboniferous assemblages of Pakistan, Yemen and South America; Carboniferous-early Permian assemblages of South Africa and Permian assemblages of Antarctica. The sediment source of the siliciclastic shelf and delta deposits intercalated in the Fenestella Shale Formation is a hinterland in which Precambrian rocks dominantly were exposed and the Th-U ratios of detrital zircons suggest, that most rocks exposed on the erosion level in the hinterland had a felsic composition. The youngest U-Pb zircon age of the investigated fossiliferous strata is 329 ± 16 Ma (late Visean to early Serpukhovian), providing a maximum age of deposition of the studied succession. Based on the affinities of the palynofloral assemblage and earlier palaeontological records, a warm, temperate and arid climate has been inferred for the Fenestella Shale Formation.
Research highlights Geochemistry and petrographical studies from the Guryul Ravine section, Jam... more Research highlights Geochemistry and petrographical studies from the Guryul Ravine section, Jammu and Kashmir, India are carried out to decipher the oceanic redox conditions at Permian-Triassic boundary (PTB) in the area. Redox sensitive elements like Ni, Co, Cr, V, U at PTB and negative Ce anamoly in the early Triassic sediments of Khunamuh Formation indicate reducing environmental conditions. The prolonged reducing conditions were probably the source of water anoxia, which may be one of the causes for the PTB mass extinction. Ternary A-CN-K plot shows moderate weathering at PTB (CIA 72), whereas, below the Late Permian Event Horizon (CIA 60), physical weathering is more prominent.
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Papers by Rajni Tewari