Stable isotopic evidence for methane seeps in Neoproterozoic postglacial cap carbonates

Ganqing Jiang (), Martin J. Kennedy and Nicholas Christie-Blick
Additional contact information
Ganqing Jiang: University of California
Martin J. Kennedy: University of California
Nicholas Christie-Blick: Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory of Columbia University

Nature, 2003, vol. 426, issue 6968, 822-826

Abstract: Abstract The Earth's most severe glaciations are thought to have occurred about 600 million years ago, in the late Neoproterozoic era1,2. 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 excursion3,4,5,6,7,8. 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’ hypothesis4,5. 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 basins3. 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 hypothesis4,5.

Date: 2003
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/nature02201 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:426:y:2003:i:6968:d:10.1038_nature02201

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/nature02201

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().