Seismic-tomography of the East-European platform: three-dimensional P-velocity model of the mantle under Fennoscandia. P. II
© Tsvetkova T.A., Shumlyanskaya L.A., Bugayenko I.V., Zayets L.N.
This paper is an extension of a set of works on seismic tomography of East European platform. A velocity pattern given corresponds to the mantle under Fenno-Scandian shield as a northwestern part of EEP. The main velocity characteristics of the mantle under the Fennoscandia, conformed along vertical and horizontal sections is common inverse property of velocity structure of the mantle. The mantle under the main part of Fennoscandia is subdivided into three groups according to its velocity characteristics. To the first group belongs the mantle under Karelian, Belomorian and Central Kola+Murmansk blocks of the Kola-Karelian mega-block, Baltic mantle block and Svekofennian block-1. To the second one belongs the under Lapland-Belomorian belt-2, Svecofennian block-2, Sveconorvegian megablock. The third group comprises the mantle areas under the Baltic block, Svecofennian block 1, Laplandian-Belomorian belt-1, which belong to transitional ones between the first and the second groups.The main borders of mantle divisibility under Fennoscandia are coordinated by both horizontal and vertical sections. They are determined by common velocity mantle characteristics, such as divisibility of the mantle according to velocity characteristics of horizontal sections, special features of velocity distribution such as presence of sub-horizontal high-velocity inclined layers, which spread from the layer of seismic lithosphere into the layer of Golitsyn-Geiko. High-velocity inclined layers separate the mantle area under Trans-Scandinavian magmatic zone and, within the limits of the mantle under Kola-Karelian mega-block, the area of distribution of mantle effects under the North Atlantics eastward.