dc.contributor.author |
Chakraborty, Nivedita
|
|
dc.contributor.author |
Sarkar, Subir
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|
dc.contributor.author |
Mandal, Anudeb
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|
dc.contributor.author |
Bumby, Adam John
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dc.date.accessioned |
2018-02-22T06:59:46Z |
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dc.date.issued |
2018-03 |
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dc.description.abstract |
Within the hydrocarbon-producing Cretaceous marine Uttatur Group, Cauvery Basin, India, the Garudamangalam Sandstone Formation is at top of a TST-HST transit. The δ13C value is expectedly depleted within the calcareous Garudamangalam Sandstone, which is the top most unit of the Uttatur Group, overlying the Karai Shale. The calcareous sandstone was deposited in a coastal setting around a shore-parallel river mouth bar. Instances of excessive depletion of δ13C up to −44.5‰ in the carbonate cement is suggestive of methane generation and its subsequent sequestration. The common occurrence of early diagenetic pyrite in these rocks testifies to the proliferation of sulfate-reducing bacteria and is suggestive of methane generation beneath the sulfate reduction zone. Upward-moving diffusive methane was possibly consumed by methanotrophs at the base of the sulfate-reduction zone. Abundant fabric-selective carbonate cement corroborates microbially-controlled anaerobic oxidation of methane. The presumed high rate of nutrient supply, abundance of vegetative material and moderately high organic carbon content in sediments (av. 1.6%), support this contention. All the samples which have the greatest δ13C depletion are characterized by enriched organic carbon and are derived from a tidal inlet-mouth facies, and selectively from mud drapes on cross-bedding in tidal strata. Calcarenite at the base of the same cross-strata are invariably much less depleted in δC13. This range of relationships indicates the transport of methanotrophs that settled on foreset beds mostly as tides slackened under the broader control of neap-spring cycles. |
en_ZA |
dc.description.department |
Geology |
en_ZA |
dc.description.embargo |
2019-03-01 |
|
dc.description.librarian |
hj2018 |
en_ZA |
dc.description.sponsorship |
SS acknowledges the Centre of Advance Study (CAS Phase V) and University with Potential for Excellence (UPE II) programmes of Jadavpur University. Geochemical work was carried out at the National Stable Isotope Facility of IIT, Kharagpur and IISER, Kolkata. |
en_ZA |
dc.description.uri |
http://www.elsevier.com/locate/marpetgeo |
en_ZA |
dc.identifier.citation |
Chakraborty, N., Sarkar, S., Mandal, A., Mandal, S., Bumby, A.,
Microenvironmental constraint on δ
13
C depletion: Garudamangalam Sandstone, Cauvery Basin, India,
Marine and Petroleum Geology (2018) 91: 776-784, doi: 10.1016/j.marpetgeo.2018.01.025. |
en_ZA |
dc.identifier.issn |
9264-8172 (print) |
|
dc.identifier.issn |
1873-4073 (online) |
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dc.identifier.other |
10.1016/j.marpetgeo.2018.01.025 |
|
dc.identifier.uri |
http://hdl.handle.net/2263/64022 |
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dc.language.iso |
en |
en_ZA |
dc.publisher |
Elsevier |
en_ZA |
dc.rights |
© 2018 Elsevier Ltd. All rights reserved. Notice : this is the author’s version of a work that was accepted for publication in Marine and Petroleum Geology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. A definitive version was subsequently published in Marine and Petroleum Geology, vol. 91, pp. 776-784, 2018. doi : 10.1016/j.marpetgeo.2018.01.025. |
en_ZA |
dc.subject |
Garudamangalam sandstone |
en_ZA |
dc.subject |
Tidal slackening |
en_ZA |
dc.subject |
Methanotrophs transportation |
en_ZA |
dc.subject |
Methane |
en_ZA |
dc.subject |
δ13C depletion |
en_ZA |
dc.subject |
Cements |
en_ZA |
dc.subject |
Methanation |
en_ZA |
dc.subject |
Organic carbon |
en_ZA |
dc.subject |
Reduction |
en_ZA |
dc.subject |
Sulfur compounds |
en_ZA |
dc.subject |
Anaerobic oxidation of methanes |
en_ZA |
dc.subject |
Carbonate cement |
en_ZA |
dc.subject |
Methanotrophs |
en_ZA |
dc.subject |
Nutrient supply |
en_ZA |
dc.subject |
Sandstone formations |
en_ZA |
dc.subject |
Sulfate reducing bacteria |
en_ZA |
dc.subject |
Sulfate reduction |
en_ZA |
dc.title |
Microenvironmental constraint on δ13C depletion : Garudamangalam Sandstone, Cauvery Basin, India |
en_ZA |
dc.type |
Postprint Article |
en_ZA |