f Sea-Floor Depressions In Parana Continental Shelf, Santos Basin

Depressions in the ocean bottom have been investigated on Santos Basin at Parana and Santa Catarina State<br>slope and shelf. Depressions are in depth range of 900 to 400 m water depths with shapes from circular (most<br>commons) to elliptical. Their diameter are from 900-1000 m to 400 m and relief from 75 to 40 m. Depressions are<br>aligned along faults parallel to shelf break. Records of 3.5 kHz shows that reflectors merge and pinch out toward<br>the center of depressions indicating that they are collapsed structures. Bottom samples have collected silty<br>sand with bivalves and detected presence of a hard ground. All these evidences associated with similar<br>examples from literature suggest that the depressions were caused by seeps of hydrocarbons. Despite not<br>being a precise tool, this technique can be used in other Brazilian basins in order to discover potential oil<br>reserves.