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Departments of the Ministry of Natural resources of Russia conduct
systematic geological survey of a continental shelf, an island and
adjoining continental land in Arctic regions. To the main kinds of works
on geological mapping concern seismic profiling, magnetometric,
gravimetric researches, well drillings, seismoacoustic profiling, with
use of a side scan and sampling of bottom sediments by corers and
dredges. Priorities of our geological knowledge of a geological
structure of a continental shelf of Russia are sheets of the State
geological map of Russia of scale 1:1 000 000, being the modern
geoinformation system (GIS) including banks of the geological and
geophysical data are.
Except for the results received within the framework of the state
programs on regional studying of a shelf and geological mapping,
materials of the state and private oil companies and the firms
conducting research and prospecting works on a shelf under licenses of
the Ministry of Natural resources are used. Seismic MSC researches
concern to them, first of all. The density of a network of seismic
survey is non-uniform for the various seas - Barents, Kara, Laptev,
East-Siberian and Chukchi Seas.
The Russian Arctic shelf on features of a geological structure is
divided on two sectors: western (Barents, White (Beloe), Kara Seas) and
east (Laptev, East-Siberian, Chukchi Seas).
The western sector is characterized by a thick sedimentary cover (up to 20
km in West – Barents Sea basin), consisting of two basic complexes:
terrigeneous Upper Paleozoic – Quaternary one, and terrigeneous – carbonate
Riphean – Mid Paleozoic platform. The ensemble of tectonic structures of the
western sector is traditionally united in Barents shelf plate. From
sedimentary basin of a southern part of Kara Sea the Barents shelf plate is
separated by a belt of early Mesozoic fold belt of Polar Urals Mountains -
Paj-Hoj – Novaya Zemlya archipelago- the Siberian threshold – Taimyr
peninsula.
East sector is subdivided into two large provinces - depressions and
raisings with Aptian - Quaternary sedimentary cover, lying on Upper Mesozoic
folded basis and large sedimentary basins with Upper Paleozoic - Quaternary
sedimentary cover. The border between different on
time of stabilization provinces is extended from De-Long's archipelago - on
the east - a southeast - to the north from Wrangel island – on an arch of
Barrow - to coast of Alaska.
The basic difference of western and eastern sectors is prevalence Upper
Cretaceous – Cenozoic sequence in eastern sector and the reduced
Cretaceous-Cenozoic interval in western sector.
The hydrocarbonic material is the basic minerals on a shelf. The estimation
of prospects of oil and gas was always one of the main tasks of studying of
the Arctic shelf of Russia. For last decades, leaning on results of direct
studying of a shelf, and in poorly investigated areas - first of all, using
the data on island and coastal land, and also extrapolating materials it is
better than the investigated foreign water areas, it was possible to
allocate the most perspective areas of a shelf, types of structures and
complexes of a sedimentary cover, to execute the general estimation of
hydrocarbonic potential. The results of this estimation are repeatedly
confirmed. These results testify that the overwhelming part of resources of
oil and gas of the Russian Arctic shelf is situated at the seas of the
western sector – Barents Sea with Pechora Sea and Kara Sea where structures
of the ancient
epicaledonian
and epihercinian platforms are situated. Thus in the Pechora
Sea resources of
oil prevail. The Carboniferous Early Permian complex contains the basic part
of these resources. Known oil deposits Prirazlomnoe, Dolginskoe, Varandej-More
and etc. are connected to it. Similar features of the oil and gas are
assumed for the northern part of Kara Sea, unfortunately, very poorly
investigated. For most part of the Barents Sea and a southern part of the
Kara Sea the main productive interval of a section is Jurassic-Cretaceous.
Discovered unique gas-content deposits Shtokmanovskoe in Barents Sea,
Rusanovskoe and Leningradskoe in the Kara
Sea are related to
the same interval.
In spite of lacking drilling, sedimentary basins of the Laptev sea are
supposed to have a high perspective deposits of oil and gas due to a unique
combination of the imposed on Upper Mesozoic basis the rift structures,
ending of Gakkel mid-oceanic ridge.
Upper Cretaceous – Cenozoic cover of southern areas of the East-Siberian and
Chukchi seas is considered as mainly gas-contained. Big perspective we are
inclined to connect with large poorly investigated North-Chukchi basin.
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