U.S. DEPARTMENT OF THE INTERIOR
U.S. GEOLOGICAL SURVEY
The Domanik-Paleozoic oil-prone total petroleum system covers most of the Timan-Pechora Basin Province of northwestern Arctic Russia. It contains nearly 20 BBOE ultimate recoverable reserves (66% oil). West of the province is the early Precambrian Eastern European craton margin. The province itself was the site of periodic Paleozoic tectonic events, culminating with the Hercynian Uralian orogeny along its eastern border. The stratigraphic record is dominated by Paleozoic platform and shelf-edge carbonates succeeded by Upper Permian to Triassic molasse siliciclastics that are locally present in depressions. Upper Devonian (Frasnian), deep marine shale and limestone source rocks – with typically 5 wt % total organic carbon – by middle Mesozoic time had generated hydrocarbons that migrated into reservoirs ranging in age from Ordovician to Triassic but most focused in Devonian and Permian rocks. Carboniferous structural inversions of old aulacogen borders, and Hercynian (Permian) to Early Cimmerian (Late Triassic to Early Jurassic) orogenic compression not only impacted depositional patterns, but also created and subsequently modified numerous structural traps within the province.
References listed in this report include a limited selection of those most recent and most pertinent to this document. Not all are specifically cited in the text. The stratigraphic equivalents chart is composited from many references to approximately equate the range of stratigraphic nomenclature in use. It is not intended to be precise with respect to absolute geologic age.
Province Boundary and Geographic Setting
The Timan-Pechora Basin Province overlies the Arctic Circle, extending across 61° -72° north latitude and 44° -66° east longitude (Figure 1). To the east, outside the province boundary, is a sinuous fold belt including the Ural Mountains, the Pay-Khoy Ridge, Vaygach Island and the Novaya Zemlya archipelago. To the west is the NW-SE trending Timan-Kanin Ridge, which intersects the Ural Mountains at the southern end of the province. The northern offshore province boundary is the South Barents transitional fault zone, separating the excluded South Barents basin of the Barents Sea from the included Pechora block within the Pechora Sea (Figure 2a). Onshore geologic features are known to extend offshore. Onshore area (70%) of this province is 315,100 sq km (121,629 sq mi) and includes the drainage basins of the Pechora, Usa, and Izhma Rivers. Offshore (30%) are 131,700 sq km (50,836 sq mi), of which approximately 5,400 sq km (2,084 sq mi) comprise islands.
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The Timan Ridge includes accreted and uplifted, slightly metamorphosed basement. It has been a west-verging thrust complex (Sobornov and Rostovshchikov, 1996) and perhaps even a left-lateral wrench zone (Ulmishek, 1988; Mezhvilk, 1995). Faults separating the Timan Ridge from the easterly adjacent Izhma-Pechora Depression have 0.5-0.8 km offsets (Bogatsky and others, 1996).