Principal Stages and Specific Features of Geotectonics in the Northern Part of the Middle Caspian

As concerns the tectonic structure of the north of the Middle Caspian there are still some debatable issues related to a complex structure of the territory near the interface of different-age large elements of the Earth’s crust – Russian and Scythian plates. The geotectonics of this water area was analyzed on the basis of structural maps prepared by PetroAlliance Services Company for LUKOIL oil company. At the first stage that began in 1996 the investigations were based on the results of 2D seismic surveys as well as previous integrating works. From 2002 the 3D surveys had been carried out in the region. Therefore, the results of 2D and 3D seismic surveys enabled for the first time in the Middle Caspian area to identify the constituent elements of the basement, to reconstruct the history of development of large Rakushechno - Shirotnay ridge and their elements. The 3D data helped to justify a complex system of strike-slip faults in the sedimentary mantle, their nature, origin, formation stages and their controlling effect during formation of multi-layer deposits.