TY - JOUR N2 - This paper presents a study of the seismic P−wave velocity and density structure of the lithosphere−asthenosphere system along a 800 km long transect extending from the actively spreading Knipovich Ridge, across southern Spitsbergen to the Kong Karls Land Volcanic Province. The 2D seismic and density model documents 6–8 km thick oceanic crust formed at the Knipovich Ridge, a distinct continent−ocean−boundary (COB), the eastern boundary of the dominantly sheared Hornsund Fault Zone, and the eastern boundary of the Early Cenozoic West Spitsbergen Fold−and−Thrust Belt. The crustal continent−ocean transitional zone has significant excess of density (more than 0.1 g/cm 3 in average), characteristic for mafic/ultramafic and high−grade metamorphic rocks. The main Caledonian suture zone between Laurentia and Barentsia is interpreted based on variations in crustal thickness, velocities and densities. A high velocity body in the lower crust is preferably interpreted in terms of Early Cretaceous magmatism channelled from an Arctic source southwards along the proto−Hornsund zone of weakness. The continental upper mantle expresses high velocities (8.24 km/s) and densities (3.2 g/cm 3 ), which may be interpreted in terms of low heat−flow and composition dominated by dunites. The lower velocities (7.85 km/s) and densities (3.1 g/cm 3 ) observed in the oceanic lithosphere suggest composition dominated by primitive peridotites. The model of mantle allows for successful direct description of subcrustal masses distribution compensating isostatically uneven crustal load. The estimated low value of correlation between density and velocity in the mantle 0.12 kg × s × m −4 suggests that horizontal density differences between oceanic and continental mantle would be dominated by compositional changes. L1 - http://journals.pan.pl/Content/99544/PDF/10183_Volume34_Issue2_01_paper.pdf L2 - http://journals.pan.pl/Content/99544 PY - 2013 IS - No 2 EP - 138 DO - 10.2478/popore−2013−0011 KW - Arctic KW - crust KW - LAB – lithosphere−asthenosphere boundary KW - gravity modelling KW - mantle composition A1 - Krysiński, Lech A1 - Grad, Marek A1 - Mjelde, Rolf A1 - Czuba, Wojciech A1 - Guterch, Aleksander PB - Polish Academy of Sciences PB - Committee on Polar Research DA - 2013 T1 - Seismic and density structure of the lithosphere−asthenosphere system along transect Knipovich Ridge−Spitsbergen−Barents Sea – geological and petrophysical implications SP - 111 UR - http://journals.pan.pl/dlibra/publication/edition/99544 T2 - Polish Polar Research ER -