Mesozoic hydrocarbon source-rocks of the Arctic region

Origin of marine petroleum source rocks from the Late Jurassic to Early Cretaceous Norwegian Greenland Seaway—evidence for stagnation and upwelling

“…Modern insights into plate tectonic evolution, structural development, sedimentology, paleoceanography, and geochemistry of strata of late Mesozoic age along the Norwegian shelf, including sediments of commercial importance, are owing to these investigations (Brekke, Dahlgren, Nyland, & Magnus, 1999;Langrock et al, 2003b;Lipinski, Warning, & Brumsack, 2003;Mutterlose et al, 2003;Smelror, Dypvik, & Mørk, 2001;Swientek & Ricken, 2001). Finegrained sediments of Late Jurassic to Early Cretaceous age occur along the eastern margin of the Norwegian-Greenland-Seaway and adjacent marginal seas (Å rhus, 1991;Doré, 1991;Doré, Lundin, Birkeland, Eliassen, & Jensen, 1997;Bugge et al, 2002;Langrock, Stein, Lipinski, & Brumsack, 2003a,b;Leith et al, 1990;Mutterlose et al, 2003;Smelror et al, 1994;Wagner & Hölemann, 1995;Worsley et al, 1988). Drilling also recovered sediments that are exceptionally rich in organic carbon and provide moderate to very good source rock potential for liquid and gaseous petroleum.…”

“…1) has been enhanced by petroleum exploration and production operations during the 1980s and early 1990s and is summarized in drilling reports and subsequent papers, e.g. by Hansen et al (1991), Jongepier, MacLeod, and Wing (1996), Leith et al (1990), Skarbø et al (1988) and Worsley, Johansen, and Kristensen (1988). Modern insights into plate tectonic evolution, structural development, sedimentology, paleoceanography, and geochemistry of strata of late Mesozoic age along the Norwegian shelf, including sediments of commercial importance, are owing to these investigations (Brekke, Dahlgren, Nyland, & Magnus, 1999;Langrock et al, 2003b;Lipinski, Warning, & Brumsack, 2003;Mutterlose et al, 2003;Smelror, Dypvik, & Mørk, 2001;Swientek & Ricken, 2001).…”

“…In higher latitudes climate changes should be more distinctively reflected in the sedimentary record than in the lower latitudes (Mutterlose et al, 2003), and the accumulation of organic carbon should be less diluted by carbonate sedimentation as it is found in the equatorial regions. Moreover, the source rock of the major oil provinces in the circum-Arctic Ocean are of Late Jurassic age (Leith et al, 1990), suggesting that formation of black shales with hydrocarbon potential are also most important (1) in true high paleolatitudes, (2) during the Jurassic-Cretaceous transition, and (3) during times of an exceptionally low sea-level compared, for example, to the mid-Cretaceous North Atlantic.…”

Upper Cretaceous/lower Tertiary black shales near the North Pole: Organic-carbon origin and source-rock potential

“…The hydrocarbons known from these circum Arctic basins probably derived from organic-carbon (OC)-rich mudrocks (''black shales''), which were deposited during Mesozoic and early Cenozoic times (Dixon et al, 1992;Leith et al, 1992;Bakke et al, 1998;Littke et al, 1999;Vyssotski et al, 2006). In the Barents Sea and northern North Atlantic off Norway, for example, organic-geochemical data from petroleum exploration drill holes representing Jurassic/ Cretaceous time intervals indicate that these black shales are characterized by very high OC contents (typically 15-25% with peak values of 430%) of a mixed marine/ terrigenous origin, probably related to anoxia and/or increased primary production (Leith et al, 1992;Langrock et al, 2003;Langrock and Stein, 2004). For the central Arctic Ocean, however, in only four short cores (FL533, FL437, FL422, and CESAR-6; Fig.…”

Paleoenvironment and sea-level change in the early Cretaceous Barents Sea?implications from near-shore marine sapropels

“…Some of these shallow marine black shales have received much commercial attention in the past because of their high petroleum source rock potential (e.g., Johansen et al 1990;Larsen et al 1990; Leith et al 1990). Much of the scientific interest in these sequences was also raised by the Mjølnir meteorite (e.g., Gudlaugsson 1993;Dypvik et al 1996), which impacted the paleo-Barents Sea close to the Volgian-Ryazanian (early/late Berriasian) boundary 142±2.6 Ma ago (e.g., Smelror et al 2001).…”