Early Famennian Trachyandesite Magmatism of the Pripyat Paleorift, East European Platform: U–Pb Age and Petrology

Abstract

On the basis of the mineralogical-petrographic and geochemical study of igneous rocks of intermediate composition of the Pripyat complex of the Late Devonian Pripyat–Dnieper magmatism area, two subphases of the Pripyat magmatism phase have been distinguished: late Fransian (Chernin or Skolodino–Chernin) with potassium specification and early Famennian (Turov–Drozdov (Yelets)) with potassium-sodium specification. For the first time, the U–Pb age of titanite from trachyandesites of the parametric Pribor borehole was estimated for rocks of Pripyat–Dnieper magmatism area at 364 ± 1 Ma. These data confirm the Famennian age of the Yelets subphase of the Pripyat phase of magmatism and make it possible to estimate the duration of the magmatic activity of this structure at least 14 m.y. taking into account the isotope dating of the earliest phases of magmatism in the Pripyat–Dnieper–Donetsk Paleorift Structure as 388 ± 12, 383.3 ± 3.8, 384.7 ± 3.9, and 383.6 ± 4.4 Ma in the Azov Region and 381 ± 2 Ma in the Pripyat–Dnieper magmatism area.