| Title | Cryogenian interglacial greenhouse driven by enhanced volcanism: evidence from mercury records |
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| Author | Zhu, T; Pan, X; Sun, R; Deng, C; Shen, J; Kwon, S Y; Grasby, S E ; Xiao, J; Yin, R |
| Source | Earth and Planetary Science Letters vol. 564, 116902, 2021 p. 1-7, https://doi.org/10.1016/j.epsl.2021.116902 |
| Image |  |
| Year | 2021 |
| Alt Series | Natural Resources Canada, Contribution Series 20210018 |
| Publisher | Elsevier |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Area | China |
| Lat/Long WENS | 100.0000 120.0000 30.0000 20.0000 |
| Subjects | environmental geology; tectonics; geochemistry; Science and Technology; Nature and Environment; paleoenvironment; paleoclimatology; glacial history; glaciation; deglaciation; interglacial stages;
volcanism; geochemical anomalies; mercury geochemistry; isotopes; organic carbon; carbon dioxide; atmospheric geochemistry; sea water geochemistry; sea sediment geochemistry; bedrock geology; lithology; sedimentary rocks; black shales;
biogeochemistry; Neoproterozoic; Cryogenian; Sturtian Glaciation; Marinoan Glaciation; Greenhouse gases; Atmospheric emissions; Climate change; Precambrian; Proterozoic |
| Illustrations | location maps; profiles; plots; schematic models |
| Program | GEM2: Geo-mapping for Energy and Minerals Western Arctic, Pearya Terrane, North Ellesmere |
| Released | 2021 04 06 |
| Abstract | An ice-free greenhouse interval (ca. 660 ~ 650 Ma) occurred between the global Sturtian (ca. 717 Ma ~ 660 Ma) and Marinoan glaciation (ca. 650 Ma ~ 635 Ma) during the Cryogenian. While volcanic CO2
emissions have been suggested as a trigger for this ice-free interval, evidence for volcanism has been lacking. In this study, spikes in both Hg concentration (76 to 366 ppb) and Hg to total organic carbon ratio (Hg/TOC: 114 to 717 ppb/wt.%) were
observed in the Wuhe section of South China, suggesting that extensive volcanic emissions of Hg occurred during the Cryogenian interglacial period. Positive Hg (0.02 to 0.18‰) values were observed in these Hg-rich shales, indicating that the volcanic
Hg was cycling in the atmosphere, deposited in seawater, and sequestered to sediment via organic matter burial. Combined with other geochemical proxies (e.g., organic carbon isotope and chemical index of alteration), our results provide the first
direct evidence that volcanism played a key role in forming the brief Cryogenian interglacial period. |
| Summary | (Plain Language Summary, not published)
This paper uses a proxy for volcanism in deep time that was developed by researchers at the NRCan to test what caused a brief pause and warm period
during a phase in Earth history known as Snow Ball Earth. The earth at this time was extensively (globally) ice covered. However there was a brief reprieve where glaciers retreated and global temperatures rapidly rose. This work demonstrates that
this reprieve in ice conditions was related to extensive volcanism releasing CO2 driving global warming. Results show that in deep earth time that global warming occurred in rapid response to CO2 emissions. |
| GEOSCAN ID | 328235 |
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