Tectonics and Hydrocarbon Potential of the Barents Megatrough

BATURIN, DMITRY, ANDREY VINOGRADOV, and ARTEM YUNOV, Laboratory of Regional Geodynamics, LARGE International, Moscow, USSR

Interpretation of geophysical data shows that the geological structure of the Eastern Barents Shelf, named Barents Megatrough (BM), extends sublongitudally almost from the Baltic shield to the Franz Josef Land archipelago.

The earth crust within the axis part of the BM is attenuated up to 28-30 km, whereas in adjacent areas its thickness exceeds 35 km.

The depression is filled with of more than 15 km of Upper Paleozoic, Mesozoic, and Cenozoic sediments overlying a folded basement of probable Caledonian age. Paleozoic sediments, with exception of the Upper Permian, are composed mainly of carbonates and evaporites. Mesozoic-Cenozoic sediments are mostly terrigenous.

The major force in the development of the BM was due to extensional tectonics. Three rifting phases are recognizable: Late Devonian-Early Carboniferous, Early Triassic, and Jurassic-Early Cretaceous.

The principal features of the geologic structure and evolution of the BM during the late Paleozoic-Mesozoic correlate well with those of the Sverdup basin, Canadian Arctic.

Significant quantity of Late Jurassic-Early Cretaceous basaltic dikes and sills were intruded within Triassic sequence during the third rifting phase. This was probably the main reason for trap disruption and hydrocarbon loss from Triassic structures.

Lower Jurassic and Lower Cretaceous reservoir sandstones are most probably the main future objects for oil and gas discoveries within the BM.

Upper Jurassic black shales are probably the main source rocks of the BM basin, as well as excellent structural traps for hydrocarbon fluids from the underlying sediments.

AAPG Search and Discovery Article #91007© 1991 AAPG International Conference, London, England, September 29-October 2, 1991 (2009)