الملخص

The Mosul depression is a topographic low which lies between the elevated anticlinal structures of bashiqa and ain safra to the northeast and atshana and nuwaigit to the southwest. This depression, some 30 km wide, is floored by the alluvial deposits of river tigris and its tributary khoser and other quaternary deposits. The present study is aimed at detecting the presence of any subsurface undulation or faulting associated with the depression. Eight points of depth electric sounding are put over a line that trends Ne-Sw across the depression Measurements were made using collinear symmetrical Schlumberger electrode arrangement with a maximum Ab distance of 1500 m. continuous correlation of the result with lithological logs of nearby wells are made. The results indicate that the traverse crosses a broad shallow sub surface undulations to the east of the tigris. The results also show that the course of the river khosar lies over an important, vertical tectonic plane ( fault ) which separates lithologies of low resistivities to the east of the river from those of high resistivities to its west.