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Silurian sedimentation in East Siberia: evidence for variations in the rate of tectonic subsidence occurring without any significant sea-level changesстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Дата последнего поиска статьи во внешних источниках: 20 января 2016 г.
- Авторы: Artyushkov E.V., Chekhovich P.A.
- Сборник: Tracing Tectonic Deformation Using the Sedimentary Record
- Серия: Spec. Publ. Geol. Soc. London
- Том: 208
- Год издания: 2003
- Издательство: Geological Society Publishing House
- Местоположение издательства: United Kingdom
- Первая страница: 321
- Последняя страница: 350
- DOI: 10.1144/GSL.SP.2003.208.01.16
- Аннотация: It is widely accepted that major variations of sea level had occurred in the Phanerozoic. Third-order cycles, 1–10 Myr long with amplitudes of 20–100 m, are of special interest for geochronology and petroleum geology. The amplitude of sea-level changes in the Silurian was estimated based on highly detailed data on the East Siberian basin, 2106 km2 in size. Fischer plots were compiled basing on thickness of 54 chronostratigraphic units — chronozones, each corresponding to time interval ~ 0.5 Myr long. A synchronism of the chronozones ensures reliable comparison of the changes occurring with time in accommodation space in different regions. The occurrence of sub-horizontal Fischer plots in several regions indicates that sea-level changes were very small in the Silurian ( 5–10 m). A mathematical analysis of relative sea-level changes, which takes into account a finite rate of crustal subsidence and different possible forms of eustatic fluctuations, shows that at the observed structure of numerous Silurian successions in East Siberia, eustatic sea-level changes of the third order could not have exceed 6–20 m. In several regions of East Siberia, the rate of crustal subsidence varied as strongly as several hundred percent at different times. These variations showed good similarity in form, but their amplitudes were different at different places in the basin. Most probably, they were caused by variations in the rate of phase transformations in mafic rocks in the lower crust. Basing on the example of East Baltic, the absence of large-scale third-order cycles in eustatic changes of sea level has been proven earlier for the Cambrian and earliest Ordovician. Probably, a similar situation was characteristic of many other epochs, when no large glaciations occurred, while many rapid changes of water depth in cratonic areas actually resulted from vertical crustal movements.
- Добавил в систему: Чехович Петр Андреевич