Stable Isotopic Evidence for Methane Seeps in Neoproterozoic Postglacial Cap Carbonates
The Earth's most severe glaciations are thought to have occurred about 600 million years ago, in the late Neoproterozoic era. A puzzling feature of glacial deposits from this interval is that they are overlain by 1–5-m-thick 'cap carbonates' (particulate deep-water marine carbonate ro...
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ftdatacite:10.7916/d8db8bzx 2023-05-15T17:11:51+02:00 Stable Isotopic Evidence for Methane Seeps in Neoproterozoic Postglacial Cap Carbonates Jiang, Ganqing Kennedy, Martin J. Christie-Blick, Nicholas 2003 https://dx.doi.org/10.7916/d8db8bzx https://academiccommons.columbia.edu/doi/10.7916/D8DB8BZX unknown Columbia University https://dx.doi.org/10.1038/nature02201 Geochemistry Geology Paleoclimatology Text Articles article-journal ScholarlyArticle 2003 ftdatacite https://doi.org/10.7916/d8db8bzx https://doi.org/10.1038/nature02201 2021-11-05T12:55:41Z The Earth's most severe glaciations are thought to have occurred about 600 million years ago, in the late Neoproterozoic era. A puzzling feature of glacial deposits from this interval is that they are overlain by 1–5-m-thick 'cap carbonates' (particulate deep-water marine carbonate rocks) associated with a prominent negative carbon isotope excursion. Cap carbonates have been controversially ascribed to the aftermath of almost complete shutdown of the ocean ecosystems for millions of years during such ice ages—the 'snowball Earth' hypothesis. Conversely, it has also been suggested that these carbonate rocks were the result of destabilization of methane hydrates during deglaciation and concomitant flooding of continental shelves and interior basins. The most compelling criticism of the latter 'methane hydrate' hypothesis has been the apparent lack of extreme isotopic variation in cap carbonates inferred locally to be associated with methane seeps. Here we report carbon isotopic and petrographic data from a Neoproterozoic postglacial cap carbonate in south China that provide direct evidence for methane-influenced processes during deglaciation. This evidence lends strong support to the hypothesis that methane hydrate destabilization contributed to the enigmatic cap carbonate deposition and strongly negative carbon isotopic anomalies following Neoproterozoic ice ages. This explanation requires less extreme environmental disturbance than that implied by the snowball Earth hypothesis. Text Methane hydrate DataCite Metadata Store (German National Library of Science and Technology) |
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Geochemistry Geology Paleoclimatology |
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Geochemistry Geology Paleoclimatology Jiang, Ganqing Kennedy, Martin J. Christie-Blick, Nicholas Stable Isotopic Evidence for Methane Seeps in Neoproterozoic Postglacial Cap Carbonates |
topic_facet |
Geochemistry Geology Paleoclimatology |
description |
The Earth's most severe glaciations are thought to have occurred about 600 million years ago, in the late Neoproterozoic era. A puzzling feature of glacial deposits from this interval is that they are overlain by 1–5-m-thick 'cap carbonates' (particulate deep-water marine carbonate rocks) associated with a prominent negative carbon isotope excursion. Cap carbonates have been controversially ascribed to the aftermath of almost complete shutdown of the ocean ecosystems for millions of years during such ice ages—the 'snowball Earth' hypothesis. Conversely, it has also been suggested that these carbonate rocks were the result of destabilization of methane hydrates during deglaciation and concomitant flooding of continental shelves and interior basins. The most compelling criticism of the latter 'methane hydrate' hypothesis has been the apparent lack of extreme isotopic variation in cap carbonates inferred locally to be associated with methane seeps. Here we report carbon isotopic and petrographic data from a Neoproterozoic postglacial cap carbonate in south China that provide direct evidence for methane-influenced processes during deglaciation. This evidence lends strong support to the hypothesis that methane hydrate destabilization contributed to the enigmatic cap carbonate deposition and strongly negative carbon isotopic anomalies following Neoproterozoic ice ages. This explanation requires less extreme environmental disturbance than that implied by the snowball Earth hypothesis. |
format |
Text |
author |
Jiang, Ganqing Kennedy, Martin J. Christie-Blick, Nicholas |
author_facet |
Jiang, Ganqing Kennedy, Martin J. Christie-Blick, Nicholas |
author_sort |
Jiang, Ganqing |
title |
Stable Isotopic Evidence for Methane Seeps in Neoproterozoic Postglacial Cap Carbonates |
title_short |
Stable Isotopic Evidence for Methane Seeps in Neoproterozoic Postglacial Cap Carbonates |
title_full |
Stable Isotopic Evidence for Methane Seeps in Neoproterozoic Postglacial Cap Carbonates |
title_fullStr |
Stable Isotopic Evidence for Methane Seeps in Neoproterozoic Postglacial Cap Carbonates |
title_full_unstemmed |
Stable Isotopic Evidence for Methane Seeps in Neoproterozoic Postglacial Cap Carbonates |
title_sort |
stable isotopic evidence for methane seeps in neoproterozoic postglacial cap carbonates |
publisher |
Columbia University |
publishDate |
2003 |
url |
https://dx.doi.org/10.7916/d8db8bzx https://academiccommons.columbia.edu/doi/10.7916/D8DB8BZX |
genre |
Methane hydrate |
genre_facet |
Methane hydrate |
op_relation |
https://dx.doi.org/10.1038/nature02201 |
op_doi |
https://doi.org/10.7916/d8db8bzx https://doi.org/10.1038/nature02201 |
_version_ |
1766068601284984832 |