Мурманская МИЛЯ. 2018 г. №4.

EXPLORATIONS Fig. 3. The scheme of regional CMP reflection seismic survey performed by JSC MAGE along with gravity and magnetic surveys on the Arctic Shelf (against the contract with the Federal Subsoil Resources Management, 2 00 4 - 2017 ). Рис. 3. Схема выполненных ОАО «МАГЭ» региональных сейсморазведочных работ МОВ ОГТ в комплексе с гравимагнитными наблюдениями на Арктическом шельфе (по заказу «Роснедра», 2 0 0 4 -2 0 1 7 годы). 20 schemes, tectonic, ecological and geologi­ cal as well as a series of structural maps and thickness maps (for the Quaternary for­ mations and Holocene). By 2010 the cover­ age extended to the Barents - Kara shelf area (in the zone up to 80° north latitude) including the Belomorian region (Fig.2). What are the problems to solve when creating and updating (permanent updating) of complete seamless maps if this approach is considered continuation of works on the Russian shelf after the program for the third generation sheets preparation? Taking into account the experience and analysis of results of seamless maps frag­ ments creation, the following conclusions may be drawn: the first requirement and approach, as a consequence, is creation of structural and seismostratigraphic basis for large isolated basins, such as the Pechora - Barents basin, North Kara, South Kara, Laptev Sea basin, East Siberian basin. In order to perform these works all the necessary data is available. The total volume of regional seismic CMP survey integrated with gravity and magnetic observations on the West Arctic shelf as well as in the Laptev Sea and in the East Siberian Sea performed by MAGE only since 2004 against the con­ tract with the Federal Agency for Mineral Resources accounts for 120,000 km (Fig.3). As a result of a real geophysical survey performed in the Barents Sea, there were dozens of local highs detected in the western sector of the Laptev Sea. Large structures with the area over 1,000 sq.km were found in the North Barents Sea. Localized forecast resources within the limits of the determined highs in the Barents, Kara and Laptev seas account for about 2.8 billion TOE [Kazanin et al., 2014]. Seismic surveys in the North Barents and Kara seas were performed right after the publication of sheets Т-37-40, Т -41-44 which are the priority object for the update. From the methodical point of view HD seismic data with deeply studied distance section offers great opportunities for the shelf geological mapping. Earlier seismoa- coustic profiling with the depth limit up to 600 m was a leading method for tracking the boundaries of the outcrop to the pre­ Quaternary surface of mapped solid rocks formations, but now the HD sections of CMP reflection make tracking more effec­ tive (Fig. 4). Seismic surveys performed over the suf­ ficiently regular survey grid allow creating 3D models of sedimentary cover structure which give an opportunity to organize and analyze the data at a new qualitative level. Fig. 4. A fragmen t of time section (reflection line GZ 1308 ), illustrating the opportunities of seismic sequences mapping. Рис. 4. Фрагмент временного разреза (про­ филь МОВ ОГТ GZ 1308 ), иллюстрирующий возможности картирования сейсмических комплексов. MURMANSK MILE • 4-2018