Gravity, magnetic, and seismic reflection data indicate that recent subsidence in the Black Sea has been associated with faulting along the southern, eastern, and northern parts of the basin. In contrast, the western margin appears to have been tectonically quiet during subsidence. A large, positive Bouguer anomaly is typical of most of the Black Sea, and free-air anomalies are usually negative. Local patterns in the gravity field suggest a separate structure for the eastern and western parts of the basin. Along most of the near-coastal parts of the sea, local variations of the gravity anomalies correlate with topography and subsurface structures displayed by the seismic profiles; in deeper water and in the southeast corner of the basin, there is no obvious correlation. T e residual magnetic field generally parallels the surrounding Caucasus and Pontic Mountains, suggesting that these structures extend partly into the Black Sea.

The southern and eastern slope of the Black Sea is characterized by a shallow basement deeply entrenched by numerous channels. In contrast, the basin slope along the northwestern side is relatively smooth, indicating little tectonic activity and a long period of sedimentation. The transition from the basin slope to basin apron on the south and east side of the Black Sea is generally abrupt; slumps and slides commonly are present at the base of the slope. In the eastern part of the basin the transition from basin slope to apron is more gentle. Most of the basin apron and the abyssal plain in the center of the Black Sea are characterized by horizontal layers that can be traced for hundreds of kilometers. South of the Crimea, these layers are disrupted by small, nearly vertical, normal f ults. This fault zone may be coincident with a northeast-southwest trend in gravity anomalies that divide the eastern and western parts of the basin. A subsurface anticline near the central part of the sea may be related to the Caucasus orogeny.