Carbon, oxygen, and strontium isotope geochemistry of the Proterozoic carbonate rocks, Bhima basin, south India: Implication for diagenesis

A carbonate dominated shallow marine Proterozoic Bhima basin consists of carbonates and clastic rocks, and is widely distributed in the northern part of the Karnataka state, south India. Limestones of the Shahabad Formation have been selected for this study and secular variations in C, O, and Sr iso...

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Main Authors: Nagarajan, Ramasamy, Armstrong-Altrin, John, Sial, Alcides, Nagendra, Raghavendra, Ellam, Rob
Format: Journal Article
Published: Universitatea de Nord din Baia Mare 2013
Subjects:
Online Access:http://www.ubm.ro/sites/CJEES/viewTopic.php?topicId=316
http://hdl.handle.net/20.500.11937/18512
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author Nagarajan, Ramasamy
Armstrong-Altrin, John
Sial, Alcides
Nagendra, Raghavendra
Ellam, Rob
author_facet Nagarajan, Ramasamy
Armstrong-Altrin, John
Sial, Alcides
Nagendra, Raghavendra
Ellam, Rob
author_sort Nagarajan, Ramasamy
building Curtin Institutional Repository
collection Online Access
description A carbonate dominated shallow marine Proterozoic Bhima basin consists of carbonates and clastic rocks, and is widely distributed in the northern part of the Karnataka state, south India. Limestones of the Shahabad Formation have been selected for this study and secular variations in C, O, and Sr isotope compositions are reported. δ13C values are varying from +3.50 to -1.38‰PDB. Similarly, the δ18O values recorded a range between -5.76 and -12.93‰PDB 87Sr/86Sr ratio for these limestones is varying between 0.70699 and 0.7117. Higher burial rate of organic matter could have been responsible for the positive δ13C values, which is common in the Proterozoic carbonate rocks. The δ18O values in most of the samples are similar to the average value of the Proterozoic carbonate rocks. Albeit some of the samples are modified in their original isotopic signature, which shows high negative δ18O values < -10‰PDB, Mn/Sr ratios > 1.5 and a negative trend between δ18O and 87Sr/86Sr, suggesting that the δ18O and 87Sr/86Sr isotopic signatures of Bhima carbonates have been altered by diagenesis. The post depositional diagenetic alteration is also supported by the petrographic characters of these carbonates.
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publishDate 2013
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spelling curtin-20.500.11937-185122017-01-30T12:08:16Z Carbon, oxygen, and strontium isotope geochemistry of the Proterozoic carbonate rocks, Bhima basin, south India: Implication for diagenesis Nagarajan, Ramasamy Armstrong-Altrin, John Sial, Alcides Nagendra, Raghavendra Ellam, Rob southern India Bhima Basin limestones diagenesis Stable isotopes A carbonate dominated shallow marine Proterozoic Bhima basin consists of carbonates and clastic rocks, and is widely distributed in the northern part of the Karnataka state, south India. Limestones of the Shahabad Formation have been selected for this study and secular variations in C, O, and Sr isotope compositions are reported. δ13C values are varying from +3.50 to -1.38‰PDB. Similarly, the δ18O values recorded a range between -5.76 and -12.93‰PDB 87Sr/86Sr ratio for these limestones is varying between 0.70699 and 0.7117. Higher burial rate of organic matter could have been responsible for the positive δ13C values, which is common in the Proterozoic carbonate rocks. The δ18O values in most of the samples are similar to the average value of the Proterozoic carbonate rocks. Albeit some of the samples are modified in their original isotopic signature, which shows high negative δ18O values < -10‰PDB, Mn/Sr ratios > 1.5 and a negative trend between δ18O and 87Sr/86Sr, suggesting that the δ18O and 87Sr/86Sr isotopic signatures of Bhima carbonates have been altered by diagenesis. The post depositional diagenetic alteration is also supported by the petrographic characters of these carbonates. 2013 Journal Article http://hdl.handle.net/20.500.11937/18512 http://www.ubm.ro/sites/CJEES/viewTopic.php?topicId=316 Universitatea de Nord din Baia Mare fulltext
spellingShingle southern India
Bhima Basin
limestones
diagenesis
Stable isotopes
Nagarajan, Ramasamy
Armstrong-Altrin, John
Sial, Alcides
Nagendra, Raghavendra
Ellam, Rob
Carbon, oxygen, and strontium isotope geochemistry of the Proterozoic carbonate rocks, Bhima basin, south India: Implication for diagenesis
title Carbon, oxygen, and strontium isotope geochemistry of the Proterozoic carbonate rocks, Bhima basin, south India: Implication for diagenesis
title_full Carbon, oxygen, and strontium isotope geochemistry of the Proterozoic carbonate rocks, Bhima basin, south India: Implication for diagenesis
title_fullStr Carbon, oxygen, and strontium isotope geochemistry of the Proterozoic carbonate rocks, Bhima basin, south India: Implication for diagenesis
title_full_unstemmed Carbon, oxygen, and strontium isotope geochemistry of the Proterozoic carbonate rocks, Bhima basin, south India: Implication for diagenesis
title_short Carbon, oxygen, and strontium isotope geochemistry of the Proterozoic carbonate rocks, Bhima basin, south India: Implication for diagenesis
title_sort carbon, oxygen, and strontium isotope geochemistry of the proterozoic carbonate rocks, bhima basin, south india: implication for diagenesis
topic southern India
Bhima Basin
limestones
diagenesis
Stable isotopes
url http://www.ubm.ro/sites/CJEES/viewTopic.php?topicId=316
http://hdl.handle.net/20.500.11937/18512