The effectiveness of the CDP seismic for investigation of sedimentation processes in rifts of the Mezen syneclise

The materials of reflection-CDP seismic investigations conducted along regional profile I – I with<br>the object of studying deep structure of the Mezen syneclise are presented. High effectiveness of<br>the work done was achieved, evaluating in acquirement of fundamentally new data on revealing<br>of deep (down to 4 – 8 km) riphean grabens carried by thick strata layering, which strata are<br>parted by sub-conformable seismic horizons. Seismic-stratigraphical analysis and paleoreconstructions<br>of riphean sediments allowed to mark out at least three floors of rift activation when<br>synrift complexes parted by post-rift epicontinental mantles were precipitating. When taking<br>seismic data under consideration, overlying marine and shoreline continental sediments of the top<br>of middle and upper riphean have been accumulating under epiplatform conditions and forming<br>continuous mantle, and were deformed and partially eroded on large basement protrusions during<br>pre-uppervendian time. There is showed that the Mezen syneclise has developed in area of active<br>rift-type continental margin, and this greatly raises the perspective of oil-and-gas presence.