Early Cretaceous Flora from the East Coast Sedimentary Basins of India: Their Chronostratigraphic and Palaeobiogeographic Significance

2021 ◽  
pp. 469-528
Author(s):  
Ch. Chinnappa ◽  
Pauline Sabina Kavali ◽  
A. Rajanikanth ◽  
Mercedes di Pasquo ◽  
M. E. C. Bernardes-de-Oliveira
Keyword(s):  
Early Cretaceous ◽  
East Coast ◽  
Sedimentary Basins

scholarly journals Late Neogene Radiolaria from the East Coast Deformed Belt, New Zealand

2021 ◽  
Author(s):  
◽  
Jeffrey Noel Ashby
Keyword(s):  
New Zealand ◽  
Southern Ocean ◽  
Ocean Circulation ◽  
Deep Water ◽  
East Coast ◽  
Sedimentary Basins ◽  
Early Pleistocene ◽  
Time Segment ◽  
Shelf Slope ◽  
Late Neogene

<p>Within the East Coast Deformed Belt there are a number of Late Neogene sedimentary basins with relatively deep-water sediments which, at places, contain abundant radiolarian skeletons. The region was subject to relatively open ocean circulation patterns during the Neogene which, combined with the input of rhyolitic glass shards, has enhanced the siliceous microfossil preservation. A short review of the silica budget is presented and discussed in relation to the preservation of siliceous microfossils in the New Zealand sequences. Techniques were developed to extract and quantitatively study fossil Radiolaria from some of the relatively barren shelf/slope sediments. One hundred and thirty-eight radiolarian taxa are described, most of which can be assigned at the generic level, but thirty-one of which can not be assigned specific names and may eventually prove to be new species. The radiolarian zonation presented is based on detailed analysis of 155 samples from 26 sections and sites ranging in age from basal Tongaporutuan (early Late Miocene) to middle Nukumaruan (early Pleistocene). Sediments of the Kapitean (uppermost Miocene) were generally deposited in shallow water environments or are missing in unconformities in the East Coast Deformed Belt, consequently the radiolarian zonation is based on very poor data in this time segment. Also upper Opoitian and Waipipian (middle Pliocene) sediments, although at places deposited in relatively deep water, generally lack siliceous tuffs, and radiolarian preservation is poor. Five major radiolarian zones can be recognised: Diartus hughesi Zone, Didymocyrtis sp. A Zone, Didymocyrtis sp. A Zone, Didymocyrtis tetrathalmus tetrathalmus Zone, Lamprocyrtis heteroporos Zone, and Lamprocyclas gamphonycha Zone. In samples with good radiolarian preservation six subzones can be identified. The Diartus hughesi Zone can be divided into the Heliodiscus umbonatum Subzone, Didymocyrtis laticonus Subzone, Heliodiscus asteriscus forma large pores Subzone, and Anthocyrtidium ehrenbergi pliocenica Subzone. Additionally the Didymocyrtis tetrathalmus tetrathalmus Zone can be divided into the Lychnocanium sp. aff. grande Subzone and Lamprocyrtis hannai Subzone. The bioevents that define the zonal boundaries are discussed along with other biostratigraphically useful radiolarian datums. These zones and zubzones are correlated to the foraminiferal zonation which in turn has been related, in part, to the paleomagnetic time scale. Correlation are then made with other radiolarian zonations in the north Pacific, tropics, and southern ocean. Points to emerge from these correlations include the apparent provincialism in the transition from Stichocorys delmontense to Stichocorys peregrine in the tropical Pacific. This transition has been reported to occur during approximately 1.5Ma but in New Zealand occurs over a time segment of at least 5.5Ma. The first appearance of Lamprocyclas gamphonycha appears to be an isochronous datum level in temperate radiolarian faunas of the northern and southern Pacific. The last appearance datum of Diartus hughesi at about 7.5Ma is in good agreement with its level in the tropics. The presence of this taxon in lower Gilbert Antarctic cores suggests either a grossly diachronous event between tropical/temperate areas and the southern ocean or, more probably, a misinterpretation of the paleomagnetic signature from key southern ocean piston cores. If the latter situation is the case then the real age estimates on the "Pre middle Gilbert" southern ocean diatom and silicoflagellate stratigraphies are questionable because they are based on the same key cores. Statistical faunal analysis shows that during the Miocene there was not much change in the radiolarian faunas with time and a major change, probably climatically controlled, took place across the Miocene/Pliocene boundary. Variability in preservation has probably affected the faunas to obscure more precise time variation although post-Miocene faunas indicate that some is present. In conclusion, the Radiolaria, although not as common in the fossil record as the foraminifera, definitely contribute to New Zealand Late Neogene integrated stratigraphy and suggest that our knowledge could be greatly enhanced by the study of other siliceous microfossil groups.</p>

scholarly journals Redescription of Arundel formation Ornithomimosaur material and a reinterpretation of Nedcolbertia justinhofmanni as an “Ostrich Dinosaur”: Biogeographic implications

2016 ◽  
Author(s):  
Chase Doran Brownstein
Keyword(s):  
United States ◽  
North America ◽  
Early Cretaceous ◽  
Fossil Record ◽  
East Coast ◽  
The United States ◽  
Eastern North America ◽  
New Taxon ◽  
Western North America ◽  
The Past

The fossil record of dinosaurs from the Early Cretaceous of eastern North America is scant, and only a few sediments to the east of the continent are fossiliferous. Among them is the Arundel Formation of the east coast of the United States, which has produced among the best dinosaur faunas known from the Early Cretaceous of eastern North America. The diverse dinosaur fauna of this formation has been thoroughly discussed previously, but few of the dinosaur species originally described from the Arundel are still regarded as valid genera. Much of the Arundel material is in need of review and redescription. Among the fossils of dinosaurs from this formation are those referred to ornithomimosaurs. Here, I redescribe ornithomimosaur remains from the Arundel Formation which may warrant the naming of a new taxon of dinosaur. These remains provide key information on the theropods of the Early Cretaceous of Eastern North America. The description of the Arundel material herein along with recent discoveries of basal ornithomimosaurs in the past 15 years has allowed for comparisons with the coelurosaur Nedcolbertia justinhofmanni, suggesting the latter animal was a basal ornithomimosaurian dinosaur rather than a “generalized” coelurosaur. Comparisons between the Arundel ornithomimosaur and similar southeast Asian ornithomimosaurian material as well as ornithomimosaur remains from western North America suggest that a lineage of ornithomimosaurs with a metatarsal condition intermediate between that of basal and derived ornithomimosaurs was present through southeast Asia into North America, in turn suggesting that such animals coexisted with genera having a more primitive metatarsal morphology as seen in N. justinhofmanni.

Exploring New Zealand's marine territory

2011 ◽  
Vol 51 (1) ◽  
pp. 549 ◽  
Author(s):  
Chris Uruski
Keyword(s):  
New Zealand ◽  
Deep Water ◽  
Seismic Data ◽  
East Coast ◽  
Sedimentary Basins ◽  
Petroleum Exploration ◽  
Seismic Survey ◽  
Data Set ◽  
Eastern Australia ◽  
Deep Water Part

Around the end of the twentieth century, awareness grew that, in addition to the Taranaki Basin, other unexplored basins in New Zealand’s large exclusive economic zone (EEZ) and extended continental shelf (ECS) may contain petroleum. GNS Science initiated a program to assess the prospectivity of more than 1 million square kilometres of sedimentary basins in New Zealand’s marine territories. The first project in 2001 acquired, with TGS-NOPEC, a 6,200 km reconnaissance 2D seismic survey in deep-water Taranaki. This showed a large Late Cretaceous delta built out into a northwest-trending basin above a thick succession of older rocks. Many deltas around the world are petroleum provinces and the new data showed that the deep-water part of Taranaki Basin may also be prospective. Since the 2001 survey a further 9,000 km of infill 2D seismic data has been acquired and exploration continues. The New Zealand government recognised the potential of its frontier basins and, in 2005 Crown Minerals acquired a 2D survey in the East Coast Basin, North Island. This was followed by surveys in the Great South, Raukumara and Reinga basins. Petroleum Exploration Permits were awarded in most of these and licence rounds in the Northland/Reinga Basin closed recently. New data have since been acquired from the Pegasus, Great South and Canterbury basins. The New Zealand government, through Crown Minerals, funds all or part of a survey. GNS Science interprets the new data set and the data along with reports are packaged for free dissemination prior to a licensing round. The strategy has worked well, as indicated by the entry of ExxonMobil, OMV and Petrobras into New Zealand. Anadarko, another new entry, farmed into the previously licensed Canterbury and deep-water Taranaki basins. One of the main results of the surveys has been to show that geology and prospectivity of New Zealand’s frontier basins may be similar to eastern Australia, as older apparently unmetamophosed successions are preserved. By extrapolating from the results in the Taranaki Basin, ultimate prospectivity is likely to be a resource of some tens of billions of barrels of oil equivalent. New Zealand’s largely submerged continent may yield continent-sized resources.

Cretaceous

1992 ◽  
Vol 13 (1) ◽  
pp. 131-139 ◽  
Author(s):  
J. M. Hancock ◽  
P. F. Rawson
Keyword(s):  
Early Cretaceous ◽  
Sedimentary Basins ◽  
Major Change ◽  
The Arctic ◽  
Sea Floor ◽  
The North ◽  
Marine Sedimentation ◽  
History Of ◽  
Sea Floor Spreading ◽  
Sea Area

AbstractEarly CretaceousThe Cretaceous Period lasted for about 70 million years. During this time there was a major change in the sedimentary history of the area as tectonism died down and deposition started of an extensive blanket of coccolith ooze: the Chalk. The change took place mainly over a brief interval across the Albian/Cenomanian (Lower/Upper Cretaceous) boundary, at about 95 Ma. Until that time crustal extension along the Arctic-North Atlantic megarifts continued to influence the tectonic evolution of northwest Europe (Ziegler 1982, 1988). This tensional régime caused rifting and block faulting, particularly across the Jurassic-Cretaceous boundary (Late Cimmerian movements) and in the mid Aptian (Austrian phase). During the latter phase, sea-floor spreading commenced in the Biscay and central Rockall Rifts. The northern part of the Rockall Rift began to widen too, possibly by crustal stretching rather than sea-floor spreading (Ziegler 1988, p. 75). During the Albian the regional pattern began to change and by the beginning of the Cenomanian rifting had effectively ceased away from the Rockall/Faeroe area.Most of the Jurassic sedimentary basins continued as depositional areas during the Early Cretaceous, but the more extensive preservation of Lower Cretaceous sediments provides firmer constraints on some of the geographical reconstructions. The marked sea-level fall across the Jurassic-Cretaceous boundary isolated the more southerly basins as areas of non-marine sedimentation, and it was not until the beginning of the Aptian that they became substantially marine.The extent of emergence of highs in the North Sea area is difficult to assess, especially where

scholarly journals Early Cretaceous flora from the Pranhita-Godavari Basin (east coast of India): taxonomic, taphonomic and palaeoecological considerations

2017 ◽  
Vol 57 (1) ◽  
pp. 13-32 ◽  
Author(s):  
Chopparapu Chinnappa ◽  
Annamraju Rajanikanth
Keyword(s):  
Plant Diversity ◽  
Early Cretaceous ◽  
East Coast ◽  
Taxonomic Diversity ◽  
East Coast Of India ◽  
Abundance Patterns ◽  
Godavari Basin

AbstractThe Early Cretaceous flora from the Gangapur Formation (Pranhita-Godavari Basin, east coast of India) was studied. Its plant diversity and abundance patterns were examined, and its palaeoecology and environment were interpreted, based on the micro- and macrofloras and sedimentological inputs. The flora is rich and diverse, and consists of bryophytes, pteridophytes, pteridosperms, gymnosperms and angiosperms. The microflora shows higher taxonomic diversity and abundance than the macroflora. Overall, the study indicated an abundance of conifers, particularly Podocarpaceae. The taphocoenosis of the flora comprises local to regional elements derived from riverbank, floodplain, backswamp and valley settings. Taken together, the data on the flora and sedimentology suggest that warm and humid environments prevailed.

EVOLUTION OF THE MESOZOIC SEDIMENTARY BASINS ON THE EAST COAST OF INDIA

1974 ◽  
Vol 14 (1) ◽  
pp. 29 ◽  
Author(s):  
V. V. Sastri ◽  
A. T. R. Raju ◽  
R. N. Sinha ◽  
B. S. Venkatachala
Keyword(s):  
Late Jurassic ◽  
East Coast ◽  
Tectonic Setting ◽  
Sedimentary Basins ◽  
Eastern Ghats ◽  
The West ◽  
East Coast Of India ◽  
Structural Style ◽  
Basin Subsidence ◽  
Basin Morphology

The stratigraphy, structure, and tectonics of the Cauvery, Godavari-Krishna, Palar, and Mahanadi Basins located on the east coast of India are considered on the basis of up-to-date surface and subsurface data with particular reference to their evolution during the Mesozoic Era.The sediments exposed in the respective basins are limited to their western and northern borders and represent a relatively smaller stratigraphic interval as compared to the sequence known to be present in the subsurface.Each of these basins is bordered to the west by down-to-the-basin faults. The structural style and recognisable regional trends of the respective basins parallel those of the Eastern Ghats which were largely responsible for their evolution during the Jurassic period. The basin morphology during Late Jurassic comprised horsts and grabens formed due to tensional forces leading to basin subsidence with localised uplifts. The close of the Mesozoic was marked by a regional easterly regression and basinal tilt and an almost complete cessation of horst and graben development and the formation of an essentially monoclinal post-Mesozoic sedimentary cover.A close similarity between the Mesozoic sedimentary basins on the east coast of India and those on the west coast of Australia is marked inasmuch as their tectonic setting, structural style, lithologic suites and faunal and palynological assemblages are concerned. The study broadly indicates that during the Late Jurassic-Early Cretaceous period the basins on the east coast of India were bordered by land masses similar to those postulated to the west of the West Australian basins.

Geological and Bioregional Assessments: assessing the prospectivity for tight, shale and deep-coal resources in the Cooper Basin, Beetaloo Subbasin and Isa Superbasin

2021 ◽  
Vol 61 (2) ◽  
pp. 477
Author(s):  
Lisa S. Hall ◽  
Meredith L. Orr ◽  
Megan E. Lech ◽  
Steven Lewis ◽  
Adam H. E. Bailey ◽  
...  
Keyword(s):  
East Coast ◽  
Sedimentary Basins ◽  
Tight Gas ◽  
Department Of Agriculture ◽  
Development Scenarios ◽  
Causal Pathways ◽  
Detailed Assessment ◽  
Gas Market ◽  
Stage 1 ◽  
Cooper Basin

The Geological and Bioregional Assessment Program is a series of independent scientific studies undertaken by Geoscience Australia and the CSIRO, supported by the Bureau of Meteorology, and managed by the Department of Agriculture, Water and the Environment. The program consists of three stages across three regions with potential to deliver gas to the East Coast Gas Market. Stage 1 was a rapid regional prioritisation conducted by Geoscience Australia, to identify those sedimentary basins with the greatest potential to deliver shale and/or tight gas to the East Coast Gas Market within the next 5–10 years. This prioritisation process assessed 27 onshore eastern and northern Australian basins with shale and/or tight gas potential. Further screening reduced this to a shortlist of nine basins where exploration was underway. The shortlisted basins were ranked on a number of criteria. The Cooper Basin, the Beetaloo Subbasin and the Isa Superbasin were selected for more detailed assessment. Stage 2 of the program involved establishing a baseline understanding of the identified regions. Geoscience Australia produced regional geological evaluations and conceptualisations that informed the assessment of shale and/or tight gas prospectivity, ground- and surface-water impacts and hydraulic fracturing models. Geoscience Australia’s relative prospectivity assessments provide an indication of where viable petroleum plays are most likely to be present. These data indicate areal and stratigraphic constraints that support the program’s further work in Stage 3, on understanding likely development scenarios, impact assessments and causal pathways.

scholarly journals O REGISTRO FÓSSIL DAS COBERTURAS SEDIMENTARES DO CRÁTON DO SÃO FRANCISCO EM MINAS GERAIS

2015 ◽  
Author(s):  
Jonathas S. Bittencourt ◽  
Matheus Kuchenbecker ◽  
André Gomide Vasconcelos ◽  
Karin E. B. Meyer
Keyword(s):  
Early Cretaceous ◽  
Fossil Record ◽  
Sedimentary Basins ◽  
Minas Gerais ◽  
The Other ◽  
Widespread Occurrence ◽  
Microbial Structures ◽  
Sedimentary Deposits ◽  
Fossil Preservation ◽  
Paleozoic Rocks

O registro fóssil dos depósitos sedimentares proterozoicos, paleozoicos e mesozoicos do Cráton do São Francisco inclui estruturas de origem microbiana (microbialitos, oncólitos), palinomorfos terrestres e marinhos, microfósseis silicosos e carbonáticos de origem marinha, metazoários neoproterozoicos, artrópodes, uma variedade de bioturbações, vertebrados actinopterígios, sarcopterígios e dinossauros. Com exceção dos microbialitos, que são amplamente distribuídos, os fósseis são relativamente escassos se comparados com a extensão geográfica dos depósitos e concentrados em alguns horizontes estratigráficos excepcionais. A raridade dos achados pode ser explicada pela falta de prospecção nas áreas mais distantes das localidades tradicionalmente conhecidas, e também ao baixo potencial de preservação dos fósseis em ambientes deposicionais do Meso e Neoproterozoico, ou de regimes climáticos extremos, i.e. glacial para o Paleozoico e desértico para as porções mesozoicas da Bacia Sanfranciscana. Trabalhos recentes de prospecção, no entanto, têm revelado um potencial significativo para novas descobertas, especialmente na região norte de Minas Gerais. Parte dos registros cenozoicos está distribuída em bacias restritas incluindo as de Gandarela e Fonseca (Eoceno-Mioceno), onde basicamente se preservou folhas de angiospermas e gimnospermas, palinomorfos e insetos, e a Bacia de Juatuba, com registro predominante de folhas de angiospermas O Quaternário constitui uma exceção do ponto de vista da diversidade e abundância de fósseis, especialmente devido à ampla ocorrência de mamíferos em sistemas cársticos. A descontinuidade dos depósitos sedimentares no Cráton do São Francisco mostram hiatos de cerca de 250 milhões de anos entre as seções fossilíferas paleozoicas e de cerca de 125 milhões de anos (Eocretáceo ao Pleistoceno) para a fauna de vertebrados. Palavras-chave: paleontologia, bacias sedimentares, registro fóssil, Proterozoico, Mesozoico, Cenozoico Abstract: THE FOSSIL RECORD OF THE SEDIMENTARY COVERS OF THE SÃO FRANCISCO CRATON IN MINAS GERAIS. The fossil record of the Proterozoic, Paleozoic and Mesozoic sedimentary deposits of the São Francisco Craton includes microbial structures (microbialites and oncoliths), terrestrial and marine palynomorphs, siliceous and calcareous marine microfossils, Neoproterozoic metazoans, arthropods, a variety of bioturbations, actinopterygians, sarcopterygians and dinosaurs. Except for the microbialites, which are widely distributed, the fossils are relatively scarce if compared with the geographic extension of the deposits and concentrated in some exceptional sedimentary horizons. The rarity of the findings can be explained by the lack of fieldwork far from the localities traditionally explored, and the low potential of fossil preservation in paleoenvironments of Paleo and Mesoproterozoic or those under extreme climatic regimes, i.e. glacial for the Paleozoic rocks and desertic for most of the Mesozoic rocks within the Sanfranciscana Basin. On the other hand, recent works have revealed a significant potential for new discoveries, especially in northern Minas Gerais. Part of the Cenozoic record is distributed across restrict basins, including Gandarela and Fonseca (Eocene-Miocene), where basically leaves of angiosperms and gymnosperms, palynomorphs and insects are preserved, and the Juatuba Basin, with predominant record of angiosperm leaves. The Quaternary is an exception of fossil diversity and abundance, due to the widespread occurrence of mammals in karstic deposits. The discontinuity of the sedimentary deposits in the São Francisco Craton shows gaps in the fossil record, which encompass c. 250 my between the Neoproterozoic and Paleozoic, and c. 125 my (Early Cretaceous to Pleistocene) for the vertebrate fauna. Keywords: paleontology, sedimentary basins, fossil record, Proterozoic, Mesozoic, Cenozoic

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