Upper Jurassic-Lower Cretaceous spore-pollen assemblages in the peninsular India

Singh, H.P.; Venkatachala, B.S.

doi:10.54991/jop.1987.1575

Cited by 7 publications

(8 citation statements)

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“…In view of these facts, the Late-Jurassic/Early Cretaceous age given to these assemblages by is corroborated by the observations made by Singh and Venkatachala (1988) that the floral changes which occurred at the Late Jurassic level continue into the Early Cretaceous. However, the lack of data on continuous sequence from Upper Jurassic to Lower Cretaceous does not permit to define the species which can demarcate the FAD for the base of Lower Cretaceous.…”

Section: XVIIIsupporting

confidence: 59%

“…which points ou t important linkage between the Katrol assemblage and Assemblage D-E of Rajmahal. On the other hand, the latter are remotely related with the Sakrigalighat which is dated as Early Cretaceous (Singh & Venkatachala, 1988). On the face value, the Lower Cretaceous Bhuj assemblage (Zone XX) and the Assemblage D-E of Rajmahal cannot be clubbed together intimately.…”

Section: Jurassic/cretaceousmentioning

confidence: 98%

“…In broader connotation the palynoassemblages so far known from Dubrajpur and Rajrnahal formations, assignable to Jurassic/Cretaceous and Lower Cretaceous (Sah & Jain, 1965;Maheshwari & Jana, 1983; --------------------- Most of these species are considered to be age determinant for the beginning of cretaceous (Venkatachala, 1974). But some of these supposedly marker of the Neocomian (Aequitriradites spinulos,us, Cicatricosisporites australiensis and Contignisporites dettmanni have been recorded from the Tithonian as well (Singh & Venkatachala, 1988;Maheshwari & Jana, 1988;Helby et aI., 1987;Burger, 1988), The consistent occurrence of these species has been definitely located at the base of Microcachryidites antarcticus Assemblage from the Cauvery Basin (Venkatachala, 1974) which qualify for Early Cretaceous. But, inspite of this valuable data, it cannot beascenained that this assemblage marks the beginning of the Early Cretaceous because there is a gap of about 195 m of sediments between Callialasporites segmentatus and Microcachryidites antarcticus Assemblages.…”

Section: XVIIImentioning

confidence: 99%

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Marker Assemblage-Zones of spores and pollen species through Gondwana Palaeozoic and Mesozoic sequence in India

Tiwari¹,

Tripathi²

1991

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Most of the palynozonation schemes so far proposed for the Gondwana sequence of India are based on quantitative representation of spore-pollen genera. These proposals have limited value for interbasinal correlation. The present synthesis deals with a model for species-based stratigraphy. Palynologically well studied Permian and Triassic sequences in the Damodar Graben and Permian, Triassic and Cretaceous sequences in the adjacent Rajmahal Basin have been taken as key regions to establish the zonation scheme. Based on the FADs and LADs and totality of composition of selected species, twenty Species Assemblage-Zones have been recognised. The reorganisation of this data through computer has also resulted in the identification of thirty Species Acme-Zones.

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Section: XVIIIsupporting

confidence: 59%

Section: Jurassic/cretaceousmentioning

confidence: 98%

Section: XVIIImentioning

confidence: 99%

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Marker Assemblage-Zones of spores and pollen species through Gondwana Palaeozoic and Mesozoic sequence in India

Tiwari¹,

Tripathi²

1991

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“…Palynology of Kutch Basin is known through a series of papers by Venkatachala and Kar (1970), Singh and Venkatachala (1987) and Jana (1983, 2004). Significant palynotaxa recorded are Concavissimisporites, Impardecispora, Bhujiasporites, Cingulatisporites, Coptospora, Aequitriradites and Cooksonites.…”

Section: Lithounitmentioning

confidence: 99%

Early Cretaceous flora of India- A review

Rajanikanth¹,

Chinnappa²

2016

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Earth’s terrestrial ecosystem during the early Cretaceous was marked by the dominance of naked seeded plants and appearance of flowering plants. Tectonic changes and evolutionary processes affected southern floras of the globe during this time. Review of Indian early Cretaceous flora distributed in peri and intra–cratonic basins signify homogenity of composition with regional variations. The flora composed of pteridophytes, pteridospermaleans, pentoxylaleans, bennettitaleans, ginkgoaleans, coniferaleans, taxaleans and taxa of uncertain affinity along with sporadic occurrence of flowering plants represent a unique Indian Early Cretaceous flora. Similitude of basinal floras with marginal differences can be attributed to taphonomic limitations and taxonomic angularity. A perusal of available data brings out an opportunity for novelty in floral composition and variable associations dictated by prevailed environmental conditions. The eastern, western and central regions of India hold distinct litho units encompassing plant mega fossils represented by leaf, wood / axis, seed, fructification and associated marker forms. Remarkable tenacity of certain plant groups, which even found in modern flora and vulnerability of many taxa constitute a blend of extinct and extant. The appearance and extinction of certain taxa can be explained as a cumulative affect of evolutionary and climatic factors. Perpetuation of gondwanic floral elements during the early Cretaceous along with newly evolved floral components testifies evolutionary innovations and changing ecological constraints.

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“…The discrepancy in the relative abundance of plant groups represented by mega-and palynofossils is bener explained by differential preservation,while abundance of pteridophytic spores indicates aUlOchthonous swampy deposition. The p'alynoflora is mainly represented by Coptospora, Microcachyridites, Crybelo-sporites, Foraminisporis, Aequitriradites, Cooksonites, Impardecispora, Cicatricosispon'tes, Neorais-trickia and Concavisporites (Ramanujam & Verma, 1977;Singh & Venkatachala, 1987). The pterido-phytic spores are represented by 103 species, gymnosperms by 26 species and bryophytes by 8 species.…”

Section: Palar Basinmentioning

confidence: 99%

Diversification and evolution of Early Cretaceous East Coast flora of India

Rajanikanth¹

1996

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The Early Cretaceous continental sediments in the East Coast of India are characterized by the Ptilophyllum flora. Interplay of tectonism and sedimentation caused plant fossil preservation in different unconnected paralic deposits distributed in Cauvery, Palar, Krishna-Godavari and Mahanadi basins and in the associated Pranhita-Godavari Graben. Plant megafossils assigned to pteridophytes, pteridosperms, cycadophytes, Taxales, Ginkgoales and Coniferales are variously distributed in these basins. Differential preservation of plant parts denotes an incomplete evolutionary pattern. Variation within the basinal flora reflects a localised aspect. Plant fossils preserved in the Cauvery, Palar, Krishna-Godavari and Mahanadi basins reflect a near shore continental sedimentary fill subjected to more dynamic events like marine transgression, which probably did not allow better preservation of plant fossils. Paucity of carbonised/silicified material, abundance of impressions of plant leaf fossils, scarcity of wood and reproductive parts indicate an unfavourable environment for plant fossil preservation in these pericratonic basins. Whereas in the associated Pranhita-Godavari Graben the plant fossils are better preserved in the sub-aerially exposed basinal areas away from the main coast-line. The Early Cretaceous flora of Cauvery, Palar and Krishna-Godavari basins dominated by cycadophytes suggests presence of seaward margins of fluviodeltaic palaeoenvironment. The pteridophyte dominant flora of Mahanadi Basin represents a decreasing marine influence contrary towards the south-eastwards. The evolution and diversification of the East Coast Early Cretaceous flora runs parallel to other intracratonic basinal flora. The uniformity in the floral component supports an equable climate. Conifers being the upland floral elements constitute chief components of intracratonic basinal flora. The fluviomarginal elements like cycadophytes predominate the pericratonic sedimentation with some upland near basinal taxa. Pteridosperms and Ginkgoales are scanty. Presence of leaves with entire margin indicates a favourable growth environment.

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Upper Jurassic-Lower Cretaceous spore-pollen assemblages in the peninsular India

Cited by 7 publications

References 0 publications

Marker Assemblage-Zones of spores and pollen species through Gondwana Palaeozoic and Mesozoic sequence in India

Marker Assemblage-Zones of spores and pollen species through Gondwana Palaeozoic and Mesozoic sequence in India

Early Cretaceous flora of India- A review

Diversification and evolution of Early Cretaceous East Coast flora of India

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