TopoEurope_SourceSink

"The role of the memory inherited by the system from the Cretaceous-Tertiary evolution of convergent margins into the build-up of the Source area" represents an individual project (IP) submitted in the framework of the Source-Sink CRP (EUROCORES project 2199). It addresses the circular shaped Apuseni Mountains (Romania) which are bordered by two basins of rather distinct character and evolution: the Miocene Pannonian basin in the west and north with a rather flat topography and the hilly Transsylvanian basin with its two-stage evolution. The northern part of the Apuseni Mountains belongs to the Tisza-unit, a microplate with mixed European and Adriatic affinity, which extends from NE Croatia into Romania and is mostly covered by the Neogene infill of the Pannonian basin. The Tisza unit presently forms a top to the NW-directed Turonian-age nappe stack which comprises from bottom to top the Mescek (only outcropping in southern Hungary), the Bihor (northern Croatia and Apuseni mountains) and the Codru (Apuseni Mountains) nappe systems. Most authors also attribute the tectonically highest Biharia nappe system to the Tisza microplate. The Biharia nappe system itself is tectonically overlain by the South Apuseni ophiolites defining the "Main Tethyan suture" between Tisza and Dacia which formed during mid-Cretaceous orogeny. However, when combining surface information in the Apuseni Mountains with subsurface information from the eastward located Transylvanian basin it becomes evident that the Biharia nappe is without interruption connected with the easterly located Bucovinian (or Getic/Supragetic) nappes of the Dacia unit. They form one and the same tectonic unit with takes the structurally highest position in the East Carpathian nappe stack. Although already partly formed during the late Jurassic, final east-directed emplacement of the Transylvanides occurred during the mid-Cretaceous. According to this correlation Turonian NW-directed thrusting led to a substantial offset of the former suture and thrusted Dacia-derived units (Biharia) against the Codru nappe system of Tisza with the western prolongation of the former suture buried underneath the Apuseni mountains. While the southern continuation of the south Apuseni Mountains into the Eastern Vardar ophiolites is well accepted there is no clear answer in the north. Either the Eastern Vardar-South Apuseni ophiolites represent the remnants of a northerly ending branch of Neotethys (failed arm) or it has to be sutured between the continuously documented Biharia-Bucovinian nappes and the underlying Codru nappe system. We expect to answer the following questions and contribute to the Source-Sink (CRP of EUROCORES project 2199) topic: Characterization of kinematics and activity of main tectonic contacts should allow for correlation with tectonic contacts in the wider Alpine Carpathian Dinarides context Characterization of the cooling and exhumation history of the Apuseni mountains, from when on did the area serve as a source region Was the exhumation of the Apuseni Mountains continuous or discontinuous both in space and in time? Were any pre-existing faults reactivated to allow for its exhumation? Is the exhumation of the Apuseni Mountains linked to the shortening in the Transylvanian basin? Are the Apuseni Mountains at least partly responsible for the distinct Tertiary tectonic evolution of the Pannonian and Transylvanian basin respectively? In order to address the posed questions we intend to apply: Field-based structural geology from ductile to brittle features Microstructural and textural analysis High to low-temperature thermochronology Petrology

Obwohl das Apusenigebirge relativ klein ist nimmt es eine Schlüsselposition für das Verständnis der gesamten Alpen-Karpaten-Dinaridenregion ein. Zwischen dem pannonischen und dem transsylvanischen Becken gelegen erlauben die Apuseniberge einen Blick durch die Miozänen Sedimente auf den Untergrund. Die gewonnenen neuen Daten zur strukturgeologischen und thermochronologischen Entwicklung dieses Gebirges während der Kreidezeit führen zu einem besseren Verständnis betreffend das Zusammenspiel zwischen den beiden involvierten Großeinheiten, der Tisza- und Dacia Einheit.Neue strukturgeologische Daten zeigen ein klareres Bild der mesozoischen polyphasen tektonischen Entwicklung insbesondere hinsichtlich Kinematik und Intensität der betroffenen Phasen. In Kombination mit geochronologischen Daten konnte so ein neues tektonisches Entwicklungsmodell für die Apuseniberge erarbeitet werden, das seinerseits wieder direkt auf die Entwicklungsmodelle der Alpen und Karpaten Einfluss nimmt und dies ebenfalls modifiziert.Die Apuseniberge stellen während der Kreide sowohl Abtragungsmaterial (source) als auch Ablagerungsräume (sink) zu Verfügung. Aus den gewonnenen Daten konnte eine bessere zeitliche und räumliche Auflösung von Zeiten erhöhter tektonischer Aktivität und damit verbundener starker Erosionstätigkeit bereitgestellt werden. Dieser direkte Zusammenhang zwischen tektonischen Phasen und Sedimentakkumulation schließt einen substantiellen Beitrag von klimatischen Komponenten hinsichtlich Sedimentanlieferung weitgehend aus,