Fieldtrip

Educational Fieldtrip

Finding the Lost Oceans: understanding the early-stage evolution of the Mesozoic Ceahlău-Severin Ocean

21-26 July 2024

Between July 21 and 26, 2024, an international educational field trip was organized in Romania and Serbia, to promote Romanian geology, particularly the Ceahlău - Severin relict oceanic suture and its passive continental margins.

There were 14 participants: PCE 50/2024 project members and collaborators (i.e., Relu Roban, Peter Luffi, Mihai Ducea, Ioan Munteanu, Constantin Ungureanu, Ciprian Stremtan), Romanian and Polish students, and professor Wojciech Stawikowski from Poland. The students are mainly members of the AAPG (American Association of Petroleum Geologists) professional scientific student chapters associated with the University of Bucharest, Romania, and Adam Mischewicz University from Poznan, Poland. On the day dedicated to the observation points in Serbia, we had the privilege of being guided by Serbian professors Uros Stojadinovic and Nevenka Djerić from the University of Belgrade.

The Carpathian Orogen preserves relicts of the Ceahlău-Severin Ocean, partly consumed by Cretaceous-Miocene subduction. In current coordinates, in the South Carpathians this oceanic suture is bordered by two continental blocks: Dacia (Getic nappes) and Danubian (various units). We analyzed the structural and stratigraphic relationships between basalts and ultramafic relicts and the host Upper Jurassic - Lower Cretaceous deep-water sediments that include radiolarites, red and green shales, and mixt turbidites (siliciclastic and carbonate). Another goal was to evaluate the sedimentary environments, looking in detail at the Lower Cretaceous sedimentary facies and sequences of the basin fill. The performed quantitative provenance analysis focused on Upper Jurassic-Lower Cretaceous sediments. The participants had the opportunity to compare the characteristics of sediments and the basement of the main potential source area, the Dacia and Danubian units, both well exposed in the field trip area.

The route covered over a 2000 km long round trip, starting from Bucharest, including the most important geological sites, located along the Ceahlău - Severin Oceanic Suture, Danubian and Getic basements, and their sedimentary covers, both in Romania and Serbia. Besides the thematic objectives, we also observed the mafic and ultramafic rock from the Danubian units along the Danube Gorge in Romania and Serbia and Transalpina route; the geothermal system of the Cerna Strike-Slip Fault (the Roman Herculane Therme) as well as the Poanoarele-Zaton karst system with its perennial lake.

In addition to the specific objectives of the educational field trip, a scientific communication session was organized on regional geology, where the research results funded by project PCE 50/ 2022 were presented in detail.

After a week spent together, future directions of collaboration between the two universities have been established and, as a result, the Romanian group will visit Poland in 2025. In addition, we have laid the foundations for a new collaboration with the University of Belgrade, we look forward to involving Serbian students in our professional field activities. The example of the regional extension of the Ceahlău-Severin oceanic suture in Serbia warns us that understanding geology should not be limited by state borders.