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Palynofra from subsurface Lower Cretaceous Intertrappean Beds in Domra Sub-basin of the Raniganj Gondwana Basin, West Bengal, India
continents, including Avalonia, Baltica, Bohemia, Cathaysia and Gondwana. The overall record of Silurian eustasy has practical applications, including assessment of tectonism, development of an ancillary time scale, reconstruction of cratonic bathymetry, and study of associated extinctions and radiations.
STRATIGRAPHY Gondwana symposium,
nine. Proceedings of the 9th international Hyderabad, January 1994. Two volumes
ed P.K.S. Guha, K. Ayyasami, S. Sengupta t R.N. Ghosh, (A.A. Balkema), Gondwana nine. Proceedings of the 9th international symposium, Hyderabad,
January 1994. Two volumes,
ISBN 9054107014, 1996, (1290 p.), index, hardback NLG225.00 The 97 papers are presented in 9 sections, each devoted to a particular theme of Gondwanan geology. Volume 1 contains Theme I: recent advances in the study of Gondwana stratigraphy, flora and fauna (34 papers); and Theme II: Gondwana palaeoclimate, palaeoenvironment and palaeogeography(8 papers). Volume 2comprises the remaining themes, III: Gondwana magmatism, tectonics and sedimentation (22 papers); IV: Gondwana of Antarctica (5 papers); V: Gondwana palaeomagnetism and deep crustal structures (4 papers) ; VI: Gondwanaland suturesin fold belts (4 papers); VII: fragmentation of Gondwanaland (7 papers); VIII: southern margins of Tethys (4 papers); and IX: coal and hydrocarbon prospects (9 papers). The Hanson Formation: a new stratigraphical unit in the Transantarctlc Mountains, Antarctica Elliot D.H., Antarctic Science, 1996, 8/4 (389-394).
The stratigraphy of the upper part of the Upper PalaeozoicLower MesozoicVictoria Groupin thecentralTransantarctic Mountains is reviewed. Marked lithologic contrasts exist in the Falla Formation between the lower volcanic-poor part and the upper volcaniclastic part. The name Falla Formation is here restricted to the lower volcanic-poor part of the sequence making it the youngest formation in the Victoria Group. The upper volcaniclastic part, a tuffaceous sequence, is named the Hanson Formation. Petrology of the Topfer Formation: first Triassic Gondwana sequence from New Zealand Mortimer N. & Smale D., Australian Journal of Earth Sciences, 1996,43/4 (467-477).
The 2 km2 outcrop of Topfer Formation is the only known sedimentary formation of Triassic age in New Zealand’s Western Province. It consists mainly of uniform medium-grained massive, well sorted felsic volcaniclastic sandstone with minor mudstone, conglomerate and coal. Two distinct petrofacies (litharenite and feldspathic litharenite) are distinguishable. The Topfer Formation is related to the Middle to Late Triassic Gondwana sequences of the Sydney Basin, Tasmania and Antarctica. Some similarities in composition of sandstones and igneous conglomerate clasts of the Topfer Formation and those of the coeval Murihiju Terrane of New Zealand’s Eastern Province suggest a common continental magmatic-arc source area. Gondwana palynostratigraphy from drill-core studies in coastal Tamil Nadu and Pondicherry Tiwari R.S., Vijaya & Tripathi A., Journal - Geological Society of India, 1996, 48/l (65-74).
The palynoflora of subsurface coal-bearing sequence in cores from boreholes TC-1 and TC-2 in Kandmanglam and Marakkanamarea,TamilNaduandPondicherryUnionTerritory has been found to be rich in pteridophytic spores. Thepalynoassemblage is assignable to the Coptospora cauveriana Zone of Aptian age. The findings add to our knowledge of Gondwana coal deposits along the east coast of India.
from Palynoflora subsurface Lower Cretaceous Intertrappean Beds in Domra Sub-basin of the Raniganj Gondwana Basin, West Bengal, India Vijaya, Cretaceous Research, 1997, 18/l (37-50).
A new sub-basin, Domra, has been located recently at the extreme Efringe ofthe Raniganj Gondwana Basin, W Bengal, India. In Domra Borehole PGD-2, the Mesozoic sequence, which is represented by live Intertrappean beds, was analysed for spores and pollen. Palynomorphs were recovered from only Intertrappean Beds 1 and 2 (263-248 m). Major elements ofthe assemblage are Callialasporites, Araucariacites, Podocarpiditesandseveralpteridophytictriletespores. Theoverall composition suggests an Early Cretaceous age. The absence of Aequitriradites, Cooksonites, Coptospora, and Triporoletes indicates that the palynoflora is older (ValanginianHauterivian) than that of the Cyclosporites hughesii Zone and closely comparable to that of the Foraminisporis wonthaggiensis Zone in Australia. Temporal relationship between cratonization and glaciation: the Vendian-early Cambrian glaciation in western Gondwana Trompette R., Palaeogeography, Palaeoclimatology, Palaeoecology, 1996, 123/l-4 (373-383).
Cratonization has long been said to favourglaciation: cratons would be ideal cradles for the development of continental icecaps. In Western Africa, the widespread continental glaciation, developed near the Proterozoic-Paleozoic boundary, can no longer be considered as Vendian. According to the recent discovery of an Early Cambrian microfauna in Eastern Senegal, it extends until Atdabanian time. In the Hoggar fold belt, it constitutes the lower part of molassic intermontane sequences where it is about 30-40 Ma younger than the PanAfrican cratonization dated at 600 Ma. In the South American Paraguay belt, glacial sequences also postdate Brasiliano cratonization dated at 590 Ma. World distribution of continents indicate that the widespread Late Vendian (?)- Early Cambrian ice cap glaciation of West Africa developed at middle latitudes (50-30”), whereas the probability Vendian glaciation of the Paraguay belt, restricted to local highlands, occupied high to middle latitudes (60”). In Western Gondwana, glaciation and cratonization occurring near the Proterozoic-Cambrian boundary appear as distinct and temporary unrelated phenomena. Comparative petrological analysis between the Permian coals of India and Western Australia: palaeoenvironments and thermal history Mishra H.K., Palaeogeography, Palaeoclimatology, Palaeoecology, 1996, 125/l-4 (119-216).
Permian sequences preserved in Western Australian basins (Collie, Perth and Canning) and the Gondwana basins of India (Damodar, Son-Mahanadi, Pench-Kanhan and Godavari Valley) have similar stratigraphic succession, fauna1 and floral assemblages, coal types and rank, and structure. The type and rank of the Permian coals indicate a similar depositional and thermal histories for the basin studied in India and Western Australia. This is consistent with the view that India and Western Australia were in close proximity before the break up of Gondwanaland. Controls on early Permian shelf deglaciation in the Karoo Basin of South Africa Visser J.N.J., Palaeogeography, Palaeoclimatology. Palaeoecology, 1996, 125/l-4 (129-139).
The Late Carboniferous to Early Permian glacigene Dwyka Group has at its top three types of transitions from diamictite to postglacial mudrock in the southern Karoo. The type 1 transition sequence consists of clast-poor carbonate-rich diamictite having a sharp contact with the overlying mudrocks. This diamicton accumulated slowly by rain-out and sediment gravity flow processes. During sehimentation the polar ice front was stabilised bv a nossible ice shelf. The tvoe 2 transitionsequenceconsistsofdlast-poordiamictitewil~sandstone bodies overlain by mudrock with ice-rafted debris or thin
STRATIGRAPHY Gondwana symposium,
nine. Proceedings of the 9th international Hyderabad, January 1994. Two volumes
ed P.K.S. Guha, K. Ayyasami, S. Sengupta t R.N. Ghosh, (A.A. Balkema), Gondwana nine. Proceedings of the 9th international symposium, Hyderabad,
January 1994. Two volumes,
ISBN 9054107014, 1996, (1290 p.), index, hardback NLG225.00 The 97 papers are presented in 9 sections, each devoted to a particular theme of Gondwanan geology. Volume 1 contains Theme I: recent advances in the study of Gondwana stratigraphy, flora and fauna (34 papers); and Theme II: Gondwana palaeoclimate, palaeoenvironment and palaeogeography(8 papers). Volume 2comprises the remaining themes, III: Gondwana magmatism, tectonics and sedimentation (22 papers); IV: Gondwana of Antarctica (5 papers); V: Gondwana palaeomagnetism and deep crustal structures (4 papers) ; VI: Gondwanaland suturesin fold belts (4 papers); VII: fragmentation of Gondwanaland (7 papers); VIII: southern margins of Tethys (4 papers); and IX: coal and hydrocarbon prospects (9 papers). The Hanson Formation: a new stratigraphical unit in the Transantarctlc Mountains, Antarctica Elliot D.H., Antarctic Science, 1996, 8/4 (389-394).
The stratigraphy of the upper part of the Upper PalaeozoicLower MesozoicVictoria Groupin thecentralTransantarctic Mountains is reviewed. Marked lithologic contrasts exist in the Falla Formation between the lower volcanic-poor part and the upper volcaniclastic part. The name Falla Formation is here restricted to the lower volcanic-poor part of the sequence making it the youngest formation in the Victoria Group. The upper volcaniclastic part, a tuffaceous sequence, is named the Hanson Formation. Petrology of the Topfer Formation: first Triassic Gondwana sequence from New Zealand Mortimer N. & Smale D., Australian Journal of Earth Sciences, 1996,43/4 (467-477).
The 2 km2 outcrop of Topfer Formation is the only known sedimentary formation of Triassic age in New Zealand’s Western Province. It consists mainly of uniform medium-grained massive, well sorted felsic volcaniclastic sandstone with minor mudstone, conglomerate and coal. Two distinct petrofacies (litharenite and feldspathic litharenite) are distinguishable. The Topfer Formation is related to the Middle to Late Triassic Gondwana sequences of the Sydney Basin, Tasmania and Antarctica. Some similarities in composition of sandstones and igneous conglomerate clasts of the Topfer Formation and those of the coeval Murihiju Terrane of New Zealand’s Eastern Province suggest a common continental magmatic-arc source area. Gondwana palynostratigraphy from drill-core studies in coastal Tamil Nadu and Pondicherry Tiwari R.S., Vijaya & Tripathi A., Journal - Geological Society of India, 1996, 48/l (65-74).
The palynoflora of subsurface coal-bearing sequence in cores from boreholes TC-1 and TC-2 in Kandmanglam and Marakkanamarea,TamilNaduandPondicherryUnionTerritory has been found to be rich in pteridophytic spores. Thepalynoassemblage is assignable to the Coptospora cauveriana Zone of Aptian age. The findings add to our knowledge of Gondwana coal deposits along the east coast of India.
from Palynoflora subsurface Lower Cretaceous Intertrappean Beds in Domra Sub-basin of the Raniganj Gondwana Basin, West Bengal, India Vijaya, Cretaceous Research, 1997, 18/l (37-50).
A new sub-basin, Domra, has been located recently at the extreme Efringe ofthe Raniganj Gondwana Basin, W Bengal, India. In Domra Borehole PGD-2, the Mesozoic sequence, which is represented by live Intertrappean beds, was analysed for spores and pollen. Palynomorphs were recovered from only Intertrappean Beds 1 and 2 (263-248 m). Major elements ofthe assemblage are Callialasporites, Araucariacites, Podocarpiditesandseveralpteridophytictriletespores. Theoverall composition suggests an Early Cretaceous age. The absence of Aequitriradites, Cooksonites, Coptospora, and Triporoletes indicates that the palynoflora is older (ValanginianHauterivian) than that of the Cyclosporites hughesii Zone and closely comparable to that of the Foraminisporis wonthaggiensis Zone in Australia. Temporal relationship between cratonization and glaciation: the Vendian-early Cambrian glaciation in western Gondwana Trompette R., Palaeogeography, Palaeoclimatology, Palaeoecology, 1996, 123/l-4 (373-383).
Cratonization has long been said to favourglaciation: cratons would be ideal cradles for the development of continental icecaps. In Western Africa, the widespread continental glaciation, developed near the Proterozoic-Paleozoic boundary, can no longer be considered as Vendian. According to the recent discovery of an Early Cambrian microfauna in Eastern Senegal, it extends until Atdabanian time. In the Hoggar fold belt, it constitutes the lower part of molassic intermontane sequences where it is about 30-40 Ma younger than the PanAfrican cratonization dated at 600 Ma. In the South American Paraguay belt, glacial sequences also postdate Brasiliano cratonization dated at 590 Ma. World distribution of continents indicate that the widespread Late Vendian (?)- Early Cambrian ice cap glaciation of West Africa developed at middle latitudes (50-30”), whereas the probability Vendian glaciation of the Paraguay belt, restricted to local highlands, occupied high to middle latitudes (60”). In Western Gondwana, glaciation and cratonization occurring near the Proterozoic-Cambrian boundary appear as distinct and temporary unrelated phenomena. Comparative petrological analysis between the Permian coals of India and Western Australia: palaeoenvironments and thermal history Mishra H.K., Palaeogeography, Palaeoclimatology, Palaeoecology, 1996, 125/l-4 (119-216).
Permian sequences preserved in Western Australian basins (Collie, Perth and Canning) and the Gondwana basins of India (Damodar, Son-Mahanadi, Pench-Kanhan and Godavari Valley) have similar stratigraphic succession, fauna1 and floral assemblages, coal types and rank, and structure. The type and rank of the Permian coals indicate a similar depositional and thermal histories for the basin studied in India and Western Australia. This is consistent with the view that India and Western Australia were in close proximity before the break up of Gondwanaland. Controls on early Permian shelf deglaciation in the Karoo Basin of South Africa Visser J.N.J., Palaeogeography, Palaeoclimatology. Palaeoecology, 1996, 125/l-4 (129-139).
The Late Carboniferous to Early Permian glacigene Dwyka Group has at its top three types of transitions from diamictite to postglacial mudrock in the southern Karoo. The type 1 transition sequence consists of clast-poor carbonate-rich diamictite having a sharp contact with the overlying mudrocks. This diamicton accumulated slowly by rain-out and sediment gravity flow processes. During sehimentation the polar ice front was stabilised bv a nossible ice shelf. The tvoe 2 transitionsequenceconsistsofdlast-poordiamictitewil~sandstone bodies overlain by mudrock with ice-rafted debris or thin