Reverse fault system Cenade-Ruşi-Veseud, effect of the Carpathian tectonic phases

The Transylvanian Basin is surrounded by the Apuseni Mountains, the Eastern Carpathians and Southern Carpathians. It has a roughly circular shape with Upper Cretaceous to Upper Miocene sedimentary fill reaching in some place up to 8 km in thickness. It is a post-tectonic basin and represents a typical back-arc basin starting to the Upper Miocene. Geological and geophysical data show that the sedimentary cover of the Transylvanian Basin has formed during at least seven sedimentary cycles: Permian – Triassic, Jurassic – Lower Cretaceous, Upper Cretaceous, Paleogene, Lower Miocene, Middle – Upper Miocene and Pliocene. Structural elements of the Transylvanian basin basement belong to the Inner Dacides, Transylvanides and Median Dacides resulted from subduction and collision processes, especially collision between the Foreapulian block and Getic block during to the Austrian tectonic phase (Albian Collision) and pre-Gossau phase. These compressional tectonic phases have generated in the Transylvanian Basin the north-south overthrust lineaments with an eastward vergence by extensional reactivation of old structures from Middle Triassic-Lower Cretaceous (normal system faults generated by the Thetysian spreading processes). Later, the Carpathian tectonic phases (Laramian, Old Styrian, New Styrian, Moldavian and Wallachian Phase), recorded, especially, in the Eastern Carpathians through the emplacement of the other Carpathian nappes (Outer Dacides, Moldavides) contributed to the thrust reactivation, some with the appearance of the new structural elements, northwards tilting of the pre-Miocene basement, basin subsidence, uplift and erosions in the Transylvania Basin.
   An example on this way is the system of Cenade-Ruşi-Veseud reverse faults, which is a result of the Wallachian tectonic phase (Pliocene/Quaternary). The Middle Badenian Salt Formation overlies the Cenade-Rusi uplift and this uplifting was generated by the thrust Laramian tectonic phase. The system of Cenade-Ruşi-Veseud reverse faults was activated at the beginning of the Pliocene and it was ruled by a combined tectonokinetic-halokinetic mechanism. The structural map with isochronous (TWT) of the top of Salt Formation shows that fault has a sinuous trend with three segments: the Cenade is on N–S direction, the Ruşi segment becomes NW-SE orientated, and the last segment, the Veseud has a WNW-ESE trending with eastward vergence and affect sedimentary deposits, including Pliocene deposits. Along this system, the Badenian Salt Formation has a column diapiric shape. Due to the very high uplift of Eastern Carpathians which occurred in the Late Miocene-Pliocene (about 4 km uplift and continues to the present day) and higher Upper Badenian-Pliocene sedimentation rates (recorded in the Eastern and Central parts of basin) combined with the Pliocene- Quaternary uplift of the Apuseni Mountains and the presence of the some strike-slip faults developed a pushing pressure of the Salt Formation toward the center and southwestern parts (salt sliding) of basin with the initiation of these reverse faults. Coevally with the Pliocene uplift of the South Carpathians (considerate as rigid fix block for the Miocene-Pliocene sediments of the Transylvanian Basin - after this uplift) were developed normal faults in the southern part of this basin, parallel to the orogen and evolution of the Cenade-Ruşi-Veseud reverse system faults don't stop, it is still activate.