Geology of San Marino

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The geology of San Marino reflects a complex and chaotic arrangement of allochthon formations, shifted into the region from the west as Liguride nappes during the Miocene Tortonian uplift. Olistrosome slump layers are exposed throughout the south of the country. Tortonian sandstone and limestone form the San Marino Series, where the town of San Marino is built. In 1977, two geologists, Bartolini and Gittoni, published research on argillite sediment in the country. Nardi and Nardi, a similar pair of geologists published their findings in 1975 of gypsum and sulfide formations related to the Messinian salinity crisis—a massive desiccation of the Mediterranean which left thick salt deposits. In the north, San Marino is overlain by Pliocene marine sediments. [1]

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Alluvium is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluvium is also sometimes called alluvial deposit. Alluvium is typically geologically young and is not consolidated into solid rock. Sediments deposited underwater, in seas, estuaries, lakes, or ponds, are not described as alluvium.

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Green River Formation

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Turbidite Geologic deposit of a turbidity current

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Facies

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The Serravallian is, in the geologic timescale, an age or a stage in the middle Miocene Epoch/Series, which spans the time between 13.82 Ma and 11.63 Ma. The Serravallian follows the Langhian and is followed by the Tortonian.

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References

  1. Moores, E.M.; Fairbridge, Rhodes W. (1997). Encyclopedia of European & Asian Regional Geology. Springer. p. 653.