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Интеллектуальная Система Тематического Исследования НАукометрических данных |
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Volgian-Hauterivian δ13C, δ18O and Mg/Ca ratios from Russian belemnites: Implications for Arctic climate and δ18O seawaterтезисы доклада
- Авторы: Nunn E.V., Price G.D., Hart M.B., Baraboshkin E.Y., Leng M.J.
- Сборник: 8th International Symposium on the Cretaceous System, Plymouth University, 6-12 September 2009, Plymouth, Abstract Volume
- Тезисы
- Год издания: 2009
- Место издания: Plymouth
- Первая страница: 164
- Последняя страница: 165
- Аннотация: This study presents new stable isotope and trace element data from belemnite rostra from the Volgian-Hauterivian interval of the Izhma River, Russia (at a palaeolatitude of ~60°N) and from the Ryazanian-Hauterivian interval of the Boyarka River, Siberia (at a palaeolatitude of ~70°N). Well preserved belemnites of the Boreal Realm genera Acroteuthis, Cylindroteuthis, Lagonibelus and Pachyteuthis were investigated. A distinct Late Valanginian positive carbon isotope excursion is identified in the marine carbonate record from both successions. The excursion occurs at a time of relatively low sea-level in Russia and Siberia, and it also leads a marked cooling episode that is observed in the Izhma River data (as indicated by the significant increase in oxygen isotope values and concomitant decrease in Mg/Ca ratios). It seems likely, that a significant burial of sediments rich in organic carbon lead to a fall in atmospheric C02 concentration and to a subsequent drop in temperature (an 'inverse greenhouse' effect).
- Добавил в систему: Барабошкин Евгений Юрьевич