@phdthesis{Sayago2014,
  author    = {Sayago, Jhosnella},
  title     = {Late Paleozoic basin analysis of the Loppa High and Finnmark Platform in the Norwegian Barents Sea : integration of seismic attributes and seismic sequence stratigraphy},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-72576},
  school      = {Universit{\"a}t Potsdam},
  pages     = {viii, 109},
  year      = {2014},
  abstract  = {The subsurface upper Palaeozoic sedimentary successions of the Loppa High half-graben and the Finnmark platform in the Norwegian Barents Sea (southwest Barents Sea) were investigated using 2D/3D seismic datasets combined with well and core data. These sedimentary successions represent a case of mixed siliciclastic-carbonates depositional systems, which formed during the earliest phase of the Atlantic rifting between Greenland and Norway. During the Carboniferous and Permian the southwest part of the Barents Sea was located along the northern margin of Pangaea, which experienced a northward drift at a speed of ~2-3 mm per year. This gradual shift in the paleolatitudinal position is reflected by changes in regional climatic conditions: from warm-humid in the early Carboniferous, changing to warm-arid in the middle to late Carboniferous and finally to colder conditions in the late Permian. Such changes in paleolatitude and climate have resulted in major changes in the style of sedimentation including variations in the type of carbonate factories. The upper Palaeozoic sedimentary succession is composed of four major depositional units comprising chronologically the Billefjorden Group dominated by siliciclastic deposition in extensional tectonic-controlled wedges, the Gipsdalen Group dominated by warm-water carbonates, stacked buildups and evaporites, the Bjarmeland Group characterized by cool-water carbonates as well as by the presence of buildup networks, and the Tempelfjorden Group characterized by fine-grained sedimentation dominated by biological silica production. In the Loppa High, the integration of a core study with multi-attribute seismic facies classification allowed highlighting the main sedimentary unconformities and mapping the spatial extent of a buried paleokarst terrain. This geological feature is interpreted to have formed during a protracted episode of subaerial exposure occurring between the late Palaeozoic and middle Triassic. Based on seismic sequence stratigraphy analysis the palaeogeography in time and space of the Loppa High basin was furthermore reconstructed and a new and more detailed tectono-sedimentary model for this area was proposed. In the Finnmark platform area, a detailed core analysis of two main exploration wells combined with key 2D seismic sections located along the main depositional profile, allowed the evaluation of depositional scenarios for the two main lithostratigraphic units: the {\O}rn Formation (Gipsdalen Group) and the Isbj{\o}rn Formation (Bjarmeland Group). During the mid-Sakmarian, two major changes were observed between the two formations including (1) the variation in the type of the carbonate factories, which is interpreted to be depth-controlled and (2) the change in platform morphology, which evolved from a distally steepened ramp to a homoclinal ramp. The results of this study may help supporting future reservoirs characterization of the upper Palaeozoic units in the Barents Sea, particularly in the Loppa High half-graben and the Finmmark platform area.},
  language  = {en}
}
@article{NickeldiPrimioMangelsdorfetal.2012,
  author    = {Nickel, Julia C. and di Primio, Rolando and Mangelsdorf, Kai and Stoddart, Daniel and Kallmeyer, Jens},
  title     = {Characterization of microbial activity in pockmark fields of the SW-Barents Sea},
  series = {Marine geology : international journal of marine geology, geochemistry and geophysics},
  volume    = {332},
  journal   = {Marine geology : international journal of marine geology, geochemistry and geophysics},
  number    = {12},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0025-3227},
  doi       = {10.1016/j.margeo.2012.02.002},
  pages     = {152 -- 162},
  year      = {2012},
  abstract  = {Multibeam bathymetry revealed the occurrence of numerous craterlike depressions, so-called pockmarks, on the sea floor of the Hammerfest Basin and the Loppa High, south-western Barents Sea. To investigate whether these pockmarks are related to ongoing gas seepage, microbial processes associated with methane metabolism were analyzed using geochemical, biogeochemical and microbiological techniques. Gravity cores were collected along transects crossing individual pockmarks, allowing a direct comparison between different locations inside (assumed activity center), on the rim, and outside of a pockmark (reference sites). Concentrations of hydrocarbons in the sediment, particularly methane, were measured as headspace (free) gas, and in the occluded and adsorbed gas fraction. Down to a depth of 2.6 m below sea floor (mbsf) sulfate reduction rates were quantified by radiotracer incubations. Concentrations of dissolved sulfate in the porewater were determined as well. Neither the sulfate profiles nor the gas measurements show any evidence of microbial activity or active fluid venting. Methane concentrations and sulfate reduction rates were extremely low or even below the detection limit. The results show that the observed sediment structures are most likely paleo-pockmarks, their formation probably occurred during the last deglaciation.},
  language  = {en}
}