Carbon reservoir perturbations induced by Deccan volcanism: Stable isotope and biomolecular perspectives from shallow marine environment in Eastern India

Geobiology ◽  
2021 ◽  
Author(s):  
Sohom Roy ◽  
Sambit Ghosh ◽  
Prasanta Sanyal
Keyword(s):  
Stable Isotope ◽  
Marine Environment ◽  
Eastern India ◽  
Deccan Volcanism ◽  
Shallow Marine ◽  
Shallow Marine Environment ◽  
Carbon Reservoir

scholarly journals Petrology and genesis of the Bhainskati iron ore deposit of Palpa District, western Nepal

2013 ◽  
Vol 15 ◽  
pp. 63-68
Author(s):  
Sujan Devkota ◽  
Lalu Prasad Paudel
Keyword(s):  
Marine Environment ◽  
Mineral Assemblage ◽  
Iron Ore ◽  
Ore Deposit ◽  
Shallow Marine ◽  
Shallow Marine Environment ◽  
Long Time ◽  
Iron Ore Deposit ◽  
Petrographic Study ◽  
Oolitic Ironstone

The Bhainskati Formation of the Tansen Group in the Palpa area is known for hematite iron ore deposit for long time. A prominent band of hematite of about 1-2 m thickness and extending >5 km was identified in the upper part of the Bhainskati Formation in the present study. The band is repeated three times in the area by folding and faulting. Petrographic study shows that it is oolitic ironstone of sedimentary origin. Main minerals in the band are hematite, goethite, quartz, calcite, siderite and albite. Hematite content varies considerably among samples and occurs mainly as oolite and cement. The Bhainskati ironstone with its ferrous mineral assemblage and well-rounded texture of the ooids suggests shallow marine environment (prodeltaic to estuarine) with reduced clastic input. DOI: http://dx.doi.org/10.3126/bdg.v15i0.7418 Bulletin of the Department of Geology, Vol. 15, 2012, pp. 63-68

Marine incursion in Upper Palaeozoic sedimentary rocks of the Oslo Region, Southern Norway

1981 ◽  
Vol 118 (3) ◽  
pp. 281-288 ◽  
Author(s):  
S. Olaussen
Keyword(s):  
Marine Environment ◽  
Rift Zone ◽  
Sedimentary Rocks ◽  
Marine Transgression ◽  
Shallow Marine ◽  
Shallow Marine Environment ◽  
Marine Fossils ◽  
Middle Carboniferous ◽  
Southern Norway

SummaryThe discovery of marine fossils in the Upper Palaeozoic of the Oslo Region suggests a previously unknown marine transgression of probable middle Carboniferous age. The fossiliferous sequence in the Oslo district was probably deposited in a very shallow marine environment as indicated by its fauna, ooids and the strong micritization of the fossils. The discovery of this sequence is consistent with the rift model for the Oslo Rift Zone, and suggests a connection with the Variscan Ocean.

Geochemical signatures of benthic foraminiferal shells from a heat-polluted shallow marine environment provide field evidence for growth and calcification under extreme warmth

2017 ◽  
Vol 23 (10) ◽  
pp. 4346-4353 ◽  
Author(s):  
Danna Titelboim ◽  
Aleksey Sadekov ◽  
Ahuva Almogi-Labin ◽  
Barak Herut ◽  
Michal Kucera ◽  
...  
Keyword(s):  
Marine Environment ◽  
Shallow Marine ◽  
Shallow Marine Environment ◽  
Field Evidence

A review of Pachyvaranus crassispondylus Arambourg, 1952, a pachyostotic marine squamate from the latest Cretaceous phosphates of Morocco and Syria

2010 ◽  
Vol 148 (2) ◽  
pp. 237-249 ◽  
Author(s):  
ALEXANDRA HOUSSAYE ◽  
NATHALIE BARDET ◽  
JEAN-CLAUDE RAGE ◽  
XABIER PEREDA SUBERBIOLA ◽  
BAÂDI BOUYA ◽  
...  
Keyword(s):  
Marine Environment ◽  
Teleost Fish ◽  
Shallow Marine ◽  
Shallow Marine Environment ◽  
Southern Margin ◽  
Mode Of Life ◽  
Aquatic Mode ◽  
The Mediterranean ◽  
Marine Reptile ◽  
Detailed Diagnosis

AbstractThe discovery of new specimens of Pachyvaranus crassispondylus Arambourg, 1952 from the Maastrichtian phosphates of Morocco and Syria enables us to (1) redescribe in detail this poorly known varanoid lizard, (2) provide a more detailed diagnosis and (3) re-evaluate the systematic affinities of this taxon within squamates. The latter is placed in Pachyvaranidae nov., considered a new unranked clade of non-pythonomorph Varanoidea. The intense pachyosteosclerosis observed in the vertebrae and ribs suggests a primarily aquatic mode of life for Pachyvaranus. This is in accordance with the sedimentological context (shallow marine environment). As for its palaeobiogeographical distribution, Pachyvaranus is a component of the marine reptile assemblages from the southern margin of the Mediterranean Tethys, around palaeolatitudes 20° N. The osteoderms previously referred to this taxon by Arambourg are reanalysed and assigned to a teleost fish.

Understanding Effects of OAE 2 in the Marginal-marine Environment: A Multi-proxy approach from Bagh Beds, Western India

2020 ◽  
Author(s):  
Bikash Ranjan Sahu ◽  
Sohom Roy ◽  
Prasanta Sanyal
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Marine Environment ◽  
Nutrient Dynamics ◽  
Isotope Composition ◽  
Western India ◽  
Organic Carbon Content ◽  
Terrestrial Environment ◽  
Shallow Marine ◽  
Carbon Reservoir

<p>The Cenomanian-Turonian (C/T) Oceanic Anoxic Event 2 (OAE 2) at ~94 million years ago was characterized by severe depletion in marine water oxygen levels and extreme perturbations in the carbon cycle at a global scale that lasted for 5 to 6-million years. However, wealth of the data comes mainly from deep marine records, hugely limiting our understanding on the contemporaneous terrestrial environmental conditions. Here, we present major and trace element concentrations, carbon isotope composition of carbonates (δ<sup>13</sup>C<sub>carb</sub>) and organic matter (δ<sup>13</sup>C<sub>bulk</sub>), organic carbon content (TOC), and biomarker composition from a ~20 m thick well-preserved shallow marine sequence from the Bagh Beds in Uchad, western India in order to investigate the nutrient dynamics, productivity variations and carbon reservoir perturbations in shallow marine as well as in terrestrial environment. Based on litho-stratigraphy, the Uchad section is divided into Lower Cenomanian, Turonian and Upper Coniacian units. A total of ~5‰ increase in the δ<sup>13</sup>C<sub>carb</sub> and 0.07% in TOC values and a sharp 1.7‰ decrease in the δ<sup>13</sup>C<sub>bulk </sub>values in Lower Cenomanian suggest large changes in organic carbon recycling before the advent of OAE 2. Higher terrigenous influx and micro-nutrient supply in the lower parts is also suggested from relatively higher concentrations of Al, Ti, Th, Fe, Zn, Ni and K, although their concentrations decrease rapidly above the C/T boundary. Significant correlation observed between δ<sup>13</sup>C<sub>bulk</sub> and δ<sup>13</sup>C<sub>carb</sub> (r=0.51, p=0.03) supports an authigenic organic matter production in the shallow marine environment. However, minor enrichments in redox-sensitive elements like Mo, V and U observed above the C/T boundary probably suggest that the shallow marine region was relatively less affected during the initial anoxic phases. Lack of correlation between redox-sensitive elements and Al or Ti concentrations (r <0.12) suggest that there is minimal influence of detrital supply on recycling of U, V and Mo. Interestingly, Lower Turonian units show large positive excursions in redox-sensitive elements as well as increases in U/Th, Ni/Co and V/(V+Ni) values, which are succeeded by a major decrease in δ<sup>13</sup>C<sub>carb </sub>values (7.6‰) and increase in the TOC values by 0.15%, thereby suggesting occurrence of a more expanded episode of anoxia in Lower Turonian that perturbed the shallow marine carbon reservoir. Ba/Al ratios are variable throughout the section, although large positive spikes preceding and succeeding the anoxic phases suggest a causal link between organic matter productivity and anoxia.</p>

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