Barents Sea: Provenance Study Controls Triassic and Jurassic Paleogeographic Restorations

Andrei Khudoley

During the past decade a number of different paleogeographic restorations was presented (e.g. Sobolev et al., 2008; Basov et al., 2009; Smelror et al., 2009; Leonchik, 2011; Henriksen et al., 2011). All of them were based mainly on interpretation of seismic data including available data from the onshore geology. Despite on similarity in major features, they are different in details regarding distribution of local depressions and highs that controlled clastic sediment paths. Recent U-Pb detrital zircon and whole-rock Sm-Nd isotopic studies clearly shows location of the main provenance that assume no significant barriers between location of provenance and its erosion products sedimentation. In Triassic sandstones, detrital zircons with age ca. 250-350 Ma predominated throughout the Barents Sea and Frantz Josef Land. Local concentrations of detrital zircons that are ca. 500-550 Ma and Paleoproterozoic in age is also documented, but, their distribution is most typical for northern Barents Sea and Frantz Josef Land and cannot be related to erosion of the Russian Craton basement or Timan Range. Nd isotopic data point to a wide distribution of juvenile rocks in provenance area. It shows that the entire Barents Sea area was supplied with clastic rocks that came from the Urals and Western Siberia basement and assumes gradual change of depositional environments in NW direction with no significant depressions or highs within the sedimentary basin. In Early and Middle Jurassic provenance areas were more variable in age and spatial distribution. Nd isotopic data show significant increasing of the evolved crust volume in provenance, whereas detrital zircon age varies from ca. 200 Ma to Archean. Although ca. 250-350 Ma grains are still numerous, significant portion of detrital zircons have ca. 430-480 Ma, 500-650 Ma, 1000-1400 Ma and Paleoproterozoic to Archean age. The Urals and Western Siberia basement provenance were still predominant, but eastern and northern lands as well as local highs supplied the Northern Barents and South Barents sedimentary basins with early Paleozoic and Precambrian grains and were important paleogeographic features that controlled distribution of clastic sediments.

AAPG Search and Discovery Article #90177©3P Arctic, Polar Petroleum Potential Conference & Exhibition, Stavanger, Norway, October 15-18, 2013