Stochastic velocity inversion of seismic reflection/refraction traveltime data for rift structure of the southwest Barents Sea
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Stochastic velocity inversion of seismic reflection/refraction traveltime data for rift structure of the southwest Barents Sea. / Clark, Stephen A.; Faleide, Jan Inge; Hauser, Juerg; Ritzmann, Oliver; Mjelde, Rolf; Ebbing, Jörg; Thybo, Hans; Flüh, Ernst.
I: Tectonophysics, Bind 593, 2013, s. 135-150.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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T1 - Stochastic velocity inversion of seismic reflection/refraction traveltime data for rift structure of the southwest Barents Sea
AU - Clark, Stephen A.
AU - Faleide, Jan Inge
AU - Hauser, Juerg
AU - Ritzmann, Oliver
AU - Mjelde, Rolf
AU - Ebbing, Jörg
AU - Thybo, Hans
AU - Flüh, Ernst
PY - 2013
Y1 - 2013
N2 - We present results from an active-source, onshore–offshore seismic reflection/refraction transect acquired as part of the PETROBAR project (Petroleum-related studies of the Barents Sea region). The 700 km-long profile is oriented NW–SE, coincident with previously published multichannel seismic reflection profiles. We utilize layer-based raytracing in a Markov Chain Monte Carlo (MCMC) inversion to determine a probabilistic velocity model constraining the sedimentary rocks, crystalline crust, and uppermost mantle in a complex tectonic regime. The profile images a wide range of crustal types and ages, from Proterozoic craton to Paleozoic to early Cenozoic rift basins; and volcanics related to Eocene continental breakup with Greenland. Our analyses indicate a complex architecture of the crystalline crust along the profile, with crystalline crustal thicknesses ranging from 43 km beneath the Varanger Peninsula to 12 km beneath the Bjørnøya Basin. Assuming an original, post-Caledonide crustal thickness of 35 km in the offshore area, we calculate the cumulative thinning (β) factors along the entire profile. The average β factor along the profile is 1.7 ± 0.1, suggesting 211–243 km of extension, consistent with the amount of overlap derived from published plate reconstructions. Local β factors approach 3, where Bjørnøya Basin reaches a depth of more than 13 km. Volcanics, carbonates, salt, diagenesis and metamorphism make deep sedimentary basin fill difficult to distinguish from original, pre-rift crystalline crust, and thus actual stretching may in places exceed our estimates.
AB - We present results from an active-source, onshore–offshore seismic reflection/refraction transect acquired as part of the PETROBAR project (Petroleum-related studies of the Barents Sea region). The 700 km-long profile is oriented NW–SE, coincident with previously published multichannel seismic reflection profiles. We utilize layer-based raytracing in a Markov Chain Monte Carlo (MCMC) inversion to determine a probabilistic velocity model constraining the sedimentary rocks, crystalline crust, and uppermost mantle in a complex tectonic regime. The profile images a wide range of crustal types and ages, from Proterozoic craton to Paleozoic to early Cenozoic rift basins; and volcanics related to Eocene continental breakup with Greenland. Our analyses indicate a complex architecture of the crystalline crust along the profile, with crystalline crustal thicknesses ranging from 43 km beneath the Varanger Peninsula to 12 km beneath the Bjørnøya Basin. Assuming an original, post-Caledonide crustal thickness of 35 km in the offshore area, we calculate the cumulative thinning (β) factors along the entire profile. The average β factor along the profile is 1.7 ± 0.1, suggesting 211–243 km of extension, consistent with the amount of overlap derived from published plate reconstructions. Local β factors approach 3, where Bjørnøya Basin reaches a depth of more than 13 km. Volcanics, carbonates, salt, diagenesis and metamorphism make deep sedimentary basin fill difficult to distinguish from original, pre-rift crystalline crust, and thus actual stretching may in places exceed our estimates.
KW - Faculty of Science
KW - Barents Sea
KW - Stretching and thinning factors
KW - Transform margin
KW - Continental rifting
KW - Crustal structure
KW - Reflection refraction velocity modeling
KW - Barents Sea
KW - Transform margin
KW - Continental rifting
KW - Crustal structure
KW - Reflection refraction velocity modeling
KW - Stretching and thinning factors
U2 - 10.1016/j.tecto.2013.02.033
DO - 10.1016/j.tecto.2013.02.033
M3 - Journal article
VL - 593
SP - 135
EP - 150
JO - Tectonophysics
JF - Tectonophysics
SN - 0040-1951
ER -
ID: 49734705