| Инд. авторы: | Ivanov A.V., Mazukabzov A.M., Stanevich A.M., Palesskiy S.V., Kozmenko O.A. |
| Заглавие: | Testing the snowball Earth hypothesis for the Ediacaran |
| Библ. ссылка: | Ivanov A.V., Mazukabzov A.M., Stanevich A.M., Palesskiy S.V., Kozmenko O.A. Testing the snowball Earth hypothesis for the Ediacaran // Geology. - 2013. - Vol.41. - Iss. 7. - P.787-790. - ISSN 0091-7613. - EISSN 1943-2682. |
| Внешние системы: | DOI: 10.1130/G34345.1; SCOPUS: 2-s2.0-84877153202; |
| Реферат: | eng: Ediacaran Siberia was at tropical paleolatitudes when the glacigenic strata of the Goloustnaya Formation (Baikal Group, Siberia) were deposited at sea level. The presence of such deposits (at tropical latitudes) is at the core of the snowball Earth hypothesis, which is generally accepted for the previous Cryogenian glaciations. To test this hypothesis for the Ediacaran Period, we determined concentrations of platinum group elements (PGE) in the transitional unit between glacigenic conglomerates and postglacial cap carbonates of the Goloustnaya Formation. We speculate that if oceans were completely covered by ice during the glaciation, the ice prevented accumulation of PGE-rich cosmic dust and micrometeorites during that period, i.e., the snowball Earth stage. Such particles would have accumulated rapidly on the ocean floor at the ice-melting event, providing a geochemical signal; however, unlike the previous Cryogenian glaciations, this signal is at a background level, and we conclude that either the Ediacaran glaciation did not reach the snowball stage, or it was of very short duration. © 2013 Geological Society of America.
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| Ключевые слова: | platinum group element; paleolatitude; paleoclimate; low temperature; lithostratigraphy; hypothesis testing; glaciation; glacial deposit; Ediacaran; concentration (composition); climate variation; Siberia; Sea level; Ice; Tropical latitudes; Snowball Earth; Short durations; Platinum group elements; Ocean floor; Cosmic dusts; Cap carbonates; Background level; Glacial geology; |
| Издано: | 2013 |
| Физ. характеристика: | с.787-790 |