Structural Evolution and Hydrocarbon Accumulation in Central Iran, Qum Region

The study area covered a segment of eastern Pomerania close to the Gdansk Bay. The region is regarded as prospective for hybrocarbon exploration. The main objective of gravity and seismic survey was to support interpretation of reflection seismic data. The problem of seismic survey in the area includes a highly reflective complex of Zechstein evaporates, which screen the propagation of seismic waves, and locally thick complex of unconsolidated sediments of Pleistocene, which severely attenuates seismic energy. As a result, poor quality data especially from sub-Zechstein complexes were often obtained. Magnetotelluric and gravity measurements were made mainly along seismic profiles. A part of gravity sites were scattered between profiles. Magnetotelluric surwey was made in two ways: as isolated soundings located at crossings of seismic profiles, and continuous profiling covering selected parts of profiles. Results of integrated gravity and magnetotelluric interpretation supplement results of seismic survey in relation to Paleozoic and Precambrian formations screened by very elastic complexes of Zechstein evaporates. A great diversity of density and resistivity in thick Silurian measures was found. Major tectonic zones in Paleozoic and Precambrian rocks were reconstructed. Results of gravity and magnetotelluric data interpretation are generally in agreement.