PALEOZOIC INTRAPLATE MAGMATISM OF THE EAST EUROPEAN PLATFORM: COMPARATIVE ANALYSIS OF THE PRIPYAT-DNIEPER-DONETS RIFT ZONE AND THE KOLA-ARKHANGELSK PROVINCE

This paper presents a comparative analysis of geochronological, geochemical, Sr-Nd isotopic data and geodynamic conditions for the Devonian magmatism of the East European Platform, using as an example the Pripyat-Dnieper-Donets rift zone in the south of the platform and the Kola alkaline province in the north. The Late Paleozoic rifting in the south of the platform was accompanied by magmatism, which formed a wide range of rocks, from alkaline-ultramafic lamprophyres and orangeites, non-diamondiferous kimberlites and carbonatites to typical tholeiites, trachyandesites, and trachyrhyodacites. Activation of rifting processes in the north of the platform has also produced a compositional diversity of magmatic occurrences dominated by kimberlites, in particular diamondiferous (Arkhangelsk diamond-bearing province), which is the main distinctive feature of the place. The Pripyat-Dnieper-Donets rift zone is subject to reverse lateral geochemical zonality of the mantle sources – from those depleted in the axial zone of the Dnieper-Donets trough to more enriched in the marginal parts – trough shoulders (Azov region, Voronezh crystalline massif): along the southeast to northwest axis of the rift zone to the Zhlobin saddle (orangeites, alkaline picrites of the Zhlobin alkaline-ultramafic complex) and in the Pripyat trough (Pripyat alkaline and subalkaline mafic complex) as well was perpendicular to the axis from the central part of the Dnieper-Donets trough to the southwest towards the Eastern Azov region (non-diamondiferous kimberlites) and to the northeast towards the Voronezh crystalline massif. Currently available petrological-mineralogical and isotopic-geochemical data on magmatites of both large magmatic structures suggest significant lithospheric heterogeneity, different types of sources of formation of rocks, and a significant influence exerted by the crustal component both in the southern and northern parts of the East European platform.