Global Climates of the Vendian: Geological Evidence
Methodological problems and the approach proposed Using paleoclimatic reconstruction methods developed for the Phanerozoic (Semikhatov, Chumakov, 2004) in the Vendian is hampered by four circumstances. The main difficulty arises because of the low resolution of Vendian chronostratigraphy when compar...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.515.8583 http://monash.edu/science/about/schools/geosciences/precsite/docs/workshop/prato04/abstracts/chumakov.pdf |
| Summary: | Methodological problems and the approach proposed Using paleoclimatic reconstruction methods developed for the Phanerozoic (Semikhatov, Chumakov, 2004) in the Vendian is hampered by four circumstances. The main difficulty arises because of the low resolution of Vendian chronostratigraphy when compared with that of the Phanerozoic. For the Vendian, interregional and especially global stratigraphic correlations can be made only to an accuracy not exceeding tens of millions of years. In two to three of the best studied sequences, the Vendian has been divided into five widely correlative units on the basis of ichno- and microfossil complexes, Ediacaran metazoan faunas, radiometric dates and stable isotope signatures, and glacial horizons (Knoll, 2000; Walter, et al., 2000). Six stratigraphic levels have been identified in White Sea sequences of the Middle Vendian based on metazoan faunal assemblages (Fedonkin, 2003). In the great majority of other Vendian sequences, the set of stratigraphic data is insufficient to subdivide and especially to globally correlate regional units. On a global scale, only three units in Vendian sequences appear to be currently distinguishable and correlatable. The remaining stratigraphic horizons noted in the Vendian System are regional. At best, interregional |
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