Fault-plane solutions for some Roumanian earthquakes and their seismotectonic implications

Twenty Roumanian earthquakes were studied. Fifteen had their foci below the earth's crust and the other five had their foci within the crust. Although the strike of the fault plane was in most cases parallel to the major geomorphologic and shallow tectonic features, the motion is prevailingly dip-slip and the shock is of the compressional type. The null vector is also preferentially oriented in a direction parallel to the same main features, particularly to the trends of the Carpathian arc and the axes of the sub-Carpathian folds. The results are integrated into the general geophysical and geological picture of the epicentral region—especially the gravity isostatic anomaly—and some conclusions are drawn concerning the deep tectonics of the Carpathian-arc-bend province. A correlation may be pointed out between present phenomena at depth and those active in the past at the surface which are responsible for the geomorphology and shallower tectonics of this geologically nodal region.