Lower-upper Permian and Triassic Seismostratigraphic Complexes in the South-eastern Barents Sea

Present evaluation of Lower-Upper Permian and Triassic clastic deposits in the Russian Barents Sea shelf are based on detailed geological and seismostratigraphic interpretation of regional seismic lines acquired by MAGE in 2007-2009. Active uncompensated subsidence of South Barents and pre-Novaya Zemlya depressions in Early-Late Permian and sea level changes led to the formation of three sequences in which low-stand, transgressive and high-stand system tracts were identified. Low stand system tracts infill central parts of the basin and contain high-amplitude discontinuous reflections which may indicate sandstones of basin fans. High-stand system tracts are characterized by sigmoid progradational reflection pattern with high-amplitude facies at clinoform bends corresponding to perspective shallow-water reservoirs. Pemian-Triassic erosion unconformity is well-traced at the basin margins. Triassic strata in the study area were formed in deltaic, coastal and shallow-marine conditions under constant compensation of basin subsidence with large volumes of sediments. They are characterized by hummocky high-amplitude reflection configuration at basin margins and low-amplitude sub-parallel discontinuous seismic pattern in the central parts. Bright, parallel, continuous reflections in the Middle Triassic correspond to sea level rise and shale deposition. Structural and stratigraphic traps were identified in Triassic complex.