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| Titel |
Late Miocene/Pliocene Ostracod Biostratigraphy from South Carpathian Foredeep, Romania (Badislava-Topolog Area) |
| VerfasserIn |
Alina Floroiu, Marius Stoica, Iuliana Vasiliev, Wout Krijgsman |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250130604
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| Publikation (Nr.) |
 EGU/EGU2016-10881.pdf |
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| Zusammenfassung |
| The Paratethys epicontinental sea has been an essential paleogeographic feature defining the
Eurasian interior since Oligocene. By the end of the Miocene, ongoing tectonic activity in the
region determined severe restrictions of the connection of the large former Paratethys sea
resulting in the formation of several smaller subbasins: the Pannonian basin, the Dacian
basin, the Black Sea and the Caspian Sea. In the western part of the Dacian Basin, the thick
and continuous Mio-Pliocene sedimentary successions of the Getic Depression of Romania
provide an exceptional opportunity to study the paleoecological changes in the Eastern
Paratethys during the time when the Mediterranean and Black Sea experienced
important sea level changes related to the Messinian Salinity Crisis. These sedimentary
successions were the basis of high-resolution magnetobiostratigraphic studies that
allow a detailed correlation to the Geological Time Scale. Here, we present the
main characteristics of the ostracod assemblages of the Late Miocene/Pliocene
sedimentary succession from Badislava-Topolog section covering the Eastern Paratethys
regional Maeotian and Pontian, stages that are, at moment, under ongoing formal
stratigraphic definition process. The Mio-Pliocene is exposed in the central part of
the Getic Depression, especially Topolog-Arges area, where it riches up to 500
m in thickness being incorporated into a large monocline structure with 15o-20o
plungeto the south. The Upper Maeotian deposits from the area have developed mainly
in fluviatile-deltaic facies with frequent continental intercalations. The ostracod
assemblage is represented by rare fresh water ostracods of Candona, Pseudocandona and
Ilyocypris genera, capable to populate unstable environments like flood-plains, lakes
and rivers with temporary existence. The scarce Maeotian ostracod fauna from
this marginal section differs essentially from the more diversified one of the same
age recorded in areas that evolved in basinal conditions. The top of the Maeotian
sequence is marked by an erosional surface. The overlaying Pontian has a transgressive
character being represented only by the Late Pontian (Bosphorian) fining-upward
sedimentary sequence that starts with coarse to medium-grained pebbles and sands in
the lower part, passing to predominant pelitic deposits to the upper part. These
Bosphorian, fine-grained sedimentary rocks provided a rich ostracods fauna represented
mainly by species of Pontoniella, Camptocypria, Caspiocypris, Cypria, Amplocypris,
Bakunella Tyrrhneocythere, Amnicythere, Loxoconcha and Amnicythere. There
are no indications for the presence of the Lower and Middle Pontian (Odessian
and Portaferrian) substages in the investigated area, the Upper Pontian deposits
discordantly overlying the Upper Maeotian sediments. The transition to the Dacian
stage (Lower Pliocene) is more gradual, some of Pontian species passing to the
Lower Dacian (Getian) where they are in association with typical Dacian ostracods. |
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