Re-Os geochronology and coupled Os-Sr isotope constraints on the Sturtian snowball Earth
After nearly a billion years with no evidence for glaciation, ice advanced to equatorial latitudes at least twice between 717 and 635 Mya. Although the initiation mechanism of these Neoproterozoic Snowball Earth events has remained a mystery, the broad synchronicity of rifting of the supercontinent...
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| Format: | Article |
| Language: | en_US |
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National Academy of Sciences (U.S.)
2014
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| Online Access: | http://hdl.handle.net/1721.1/89082 |
| _version_ | 1826188633212715008 |
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| author | Dudas, Francis O. Hallman, Christian Rooney, Alan D. Macdonald, Francis A. Strauss, Justin V. Selby, David |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Dudas, Francis O. Hallman, Christian Rooney, Alan D. Macdonald, Francis A. Strauss, Justin V. Selby, David |
| author_sort | Dudas, Francis O. |
| collection | MIT |
| description | After nearly a billion years with no evidence for glaciation, ice advanced to equatorial latitudes at least twice between 717 and 635 Mya. Although the initiation mechanism of these Neoproterozoic Snowball Earth events has remained a mystery, the broad synchronicity of rifting of the supercontinent Rodinia, the emplacement of large igneous provinces at low latitude, and the onset of the Sturtian glaciation has suggested a tectonic forcing. We present unique Re-Os geochronology and high-resolution Os and Sr isotope profiles bracketing Sturtian-age glacial deposits of the Rapitan Group in northwest Canada. Coupled with existing U-Pb dates, the postglacial Re-Os date of 662.4 ± 3.9 Mya represents direct geochronological constraints for both the onset and demise of a Cryogenian glaciation from the same continental margin and suggests a 55-My duration of the Sturtian glacial epoch. The Os and Sr isotope data allow us to assess the relative weathering input of old radiogenic crust and more juvenile, mantle-derived substrate. The preglacial isotopic signals are consistent with an enhanced contribution of juvenile material to the oceans and glacial initiation through enhanced global weatherability. In contrast, postglacial strata feature radiogenic Os and Sr isotope compositions indicative of extensive glacial scouring of the continents and intense silicate weathering in a post–Snowball Earth hothouse. |
| first_indexed | 2024-09-23T08:02:40Z |
| format | Article |
| id | mit-1721.1/89082 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T08:02:40Z |
| publishDate | 2014 |
| publisher | National Academy of Sciences (U.S.) |
| record_format | dspace |
| spelling | mit-1721.1/890822022-09-30T01:54:21Z Re-Os geochronology and coupled Os-Sr isotope constraints on the Sturtian snowball Earth Dudas, Francis O. Hallman, Christian Rooney, Alan D. Macdonald, Francis A. Strauss, Justin V. Selby, David Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Dudas, Francis O. Hallman, Christian After nearly a billion years with no evidence for glaciation, ice advanced to equatorial latitudes at least twice between 717 and 635 Mya. Although the initiation mechanism of these Neoproterozoic Snowball Earth events has remained a mystery, the broad synchronicity of rifting of the supercontinent Rodinia, the emplacement of large igneous provinces at low latitude, and the onset of the Sturtian glaciation has suggested a tectonic forcing. We present unique Re-Os geochronology and high-resolution Os and Sr isotope profiles bracketing Sturtian-age glacial deposits of the Rapitan Group in northwest Canada. Coupled with existing U-Pb dates, the postglacial Re-Os date of 662.4 ± 3.9 Mya represents direct geochronological constraints for both the onset and demise of a Cryogenian glaciation from the same continental margin and suggests a 55-My duration of the Sturtian glacial epoch. The Os and Sr isotope data allow us to assess the relative weathering input of old radiogenic crust and more juvenile, mantle-derived substrate. The preglacial isotopic signals are consistent with an enhanced contribution of juvenile material to the oceans and glacial initiation through enhanced global weatherability. In contrast, postglacial strata feature radiogenic Os and Sr isotope compositions indicative of extensive glacial scouring of the continents and intense silicate weathering in a post–Snowball Earth hothouse. Agouron Institute 2014-08-28T14:21:20Z 2014-08-28T14:21:20Z 2014-01 2013-06 Article http://purl.org/eprint/type/JournalArticle 0027-8424 1091-6490 http://hdl.handle.net/1721.1/89082 Rooney, A. D., F. A. Macdonald, J. V. Strauss, F. O. Dudas, C. Hallmann, and D. Selby. “Re-Os Geochronology and Coupled Os-Sr Isotope Constraints on the Sturtian Snowball Earth.” Proceedings of the National Academy of Sciences 111, no. 1 (December 16, 2013): 51–56. en_US http://dx.doi.org/10.1073/pnas.1317266110 Proceedings of the National Academy of Sciences Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf National Academy of Sciences (U.S.) PNAS |
| spellingShingle | Dudas, Francis O. Hallman, Christian Rooney, Alan D. Macdonald, Francis A. Strauss, Justin V. Selby, David Re-Os geochronology and coupled Os-Sr isotope constraints on the Sturtian snowball Earth |
| title | Re-Os geochronology and coupled Os-Sr isotope constraints on the Sturtian snowball Earth |
| title_full | Re-Os geochronology and coupled Os-Sr isotope constraints on the Sturtian snowball Earth |
| title_fullStr | Re-Os geochronology and coupled Os-Sr isotope constraints on the Sturtian snowball Earth |
| title_full_unstemmed | Re-Os geochronology and coupled Os-Sr isotope constraints on the Sturtian snowball Earth |
| title_short | Re-Os geochronology and coupled Os-Sr isotope constraints on the Sturtian snowball Earth |
| title_sort | re os geochronology and coupled os sr isotope constraints on the sturtian snowball earth |
| url | http://hdl.handle.net/1721.1/89082 |
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