CRETACEOUS TO MIOCENE THRUSTING AND WRENCHING ALONG THE CENTRAL SOUTHCARPATHIANS DUE TO A CORNER EFFECT DURING COLLISION AND OROCLINE FORMATION

Field studies in the Romanian South Carpathians (longitude 22.5-degree s to 24.2-degrees-E and latitude 45.20 to 45.6-degrees-N) demonstrate (1) Cretaceous top-to-NE shearing parallel to the present strike of th e thrust system connected with coaxial flattening within the generally northwest dipping foliation, (2) Paleogene ductile-brittle dextral wr enching, E-W compression (sigma1:87+/-15-degrees), and basin formation (Petrosani basin) along the Cerna-Jiu fault system, (3) large-scale M iocene dextral wrenching along the northern margin of Moesia (sigma1:1 43+/-16-degrees), and (4) probably Pliocene-early Pleistocene N-S comp ression (sigma1:205+/-25-degrees). We discuss the tectonics of the Sou th Carpathians stressing the corner effect of the Moesian foreland pro montory during convergence and formation of the Carpathian orocline. U p to the late Early Cretaceous subduction of oceanic crust was active between Europe-Moesia on one side and East Carpathia-Rhodopia on the o ther side. Collision and intracontinental deformation occurred during the late Early and Late Cretaceous. The pinning of the thrust front at the western tip of Moesia and the foreland recess north of it caused superposition of thrusting and wrenching during collision and lateral translation, tangential stretching during orocline formation, and spre ading into the recess. Further convergence during the early Tertiary r esulted in dislocation of the previously welded East Carpathian-Rhodop ian and Moesian fragments along the Cerna-Jiu fault system and the fur ther northeast translation of the western segment. The intramontane Pe trosani basin opened as a northeasterly propagating, transient pull-ap art structure along the Cerna-Jiu fault system, which acquired a curve d, north-easterly convex, transtensional trace due to the shape of the Moesian promontory. Tightening of the Carpathian orocline and/or rear rangement of the microplate geometry during the formation of the Panno nian basin system led to large-scale dextral wrenching along the north ern margin of Moesia. Pliocene N-S compression reflects final shorteni ng in the Carpathian system before ongoing convergence between Europe and Africa was transferred to the Mediterranean. Rotation of material lines around the Moesian corner is corroborated by paleomagnetic studi es.