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MN 4 (biostratigraphic Zone)
In biostratigraphy, MN 4 is one of the MN zones used to characterize the fossil mammal faunas of the Neogene of Europe. It is preceded by MN 3 and followed by MN 5; together, these three zones form the Orleanian age of the middle Miocene. This zone starts within magnetostratigraphic chron C5Dr, at 18 million years ago, and ends within chron C5Cr, at 17.0 million years ago, although some different correlations have been proposed.Steininger, 1999, p. 16 The reference locality used to correlate faunas with this zone is La Romieu (southwestern France); other localities include Artesilla and Buñol in Spain, Tägernaustrasse-Jona in Switzerland, Erkertshofen 2 and Petersbuch 2 in Germany, Belchatov C in Poland, and Aliveri in Greece.Mein, 1999, p. 28 In this zone, the common muroid rodent '' Democricetodon'' immigrates into Europe from Asia, followed shortly after by three other muroids: '' Megacricetodon'', '' Eumyarion'', and '' Anomalomys''. '' Cricetodon'', which later also r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biostratigraphy
Biostratigraphy is the branch of stratigraphy which focuses on correlating and assigning relative ages of rock Stratum, strata by using the fossil assemblages contained within them.Hine, Robert. “Biostratigraphy.” ''Oxford Reference: Dictionary of Biology'', 8th ed., Oxford University Press, 2019. The primary objective of biostratigraphy is ''correlation'', demonstrating that a particular Horizon (geology), horizon in one geological section represents the same period of time as another horizon at a different section. Fossils within these strata are useful because sediments of the same age can look completely different, due to local variations in the Sedimentary depositional environment, sedimentary environment. For example, one section might have been made up of clays and marls, while another has more chalky limestones. However, if the fossil species recorded are similar, the two sediments are likely to have been laid down around the same time. Ideally these fossils are used to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
