Paleoenvironmental evolution of the East Carpathian foredeep during the late Miocene–early Pliocene (Dacian Basin; Romania)

• Published in: Global and planetary change 2013-04, Vol.103, p.135-148
• Main Authors: Stoica, M., Lazăr, I., Krijgsman, W., Vasiliev, I., Jipa, D., Floroiu, A.
• Format: Article
• Language: English
• Subjects: biostratigraphy; Carpathian foredeep; Dacian Basin; Messinian; ostracods; paleoenvironment; Paratethys
• ISSN: 0921-8181; 1872-6364
• DOI: 10.1016/j.gloplacha.2012.04.004

The thick and continuous Mio-Pliocene sedimentary successions of the Focşani Depression in the Dacian Basin of Romania provide an excellent opportunity to study the paleoecological changes in the Eastern Paratethys during the time when the Mediterranean and Black Sea experienced major sea level fluctuations related to the closure and re-opening of the marine connection to the Atlantic Ocean during the Messinian Salinity Crisis. These successions form the basis of high-resolution magneto-biostratigraphic studies that allow a detailed correlation to the standard Geological Time Scale. Here, we analyze the paleoenvironmental evolution of the East Carpathian foredeep by integrating micro- and macropaleontological data and sedimentological analyses. The ostracod and mollusc fossil associations from the Râmnicu Sărat river section indicate that the late Maeotian depositional environment was characterized by shallow waters and littoral to fluvio-deltaic sediments. The Maeotian–Pontian boundary (6.04Ma) is marked by a marine ingression, comprising benthic (agglutinated and calcareous) and planktonic (Streptochilus spp.) foraminifera and nanofossils. Following this marine ingression, the Lower Pontian (Odessian; 6.04–5.8Ma) fauna shows an increased bathymetry of the basin. The presence of ostracod species with eye tubercles indicates depositional environments within the photic zone (