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U‐Pb age and Hf isotope compositions of zircons from the north‐western region of the Ukrainian shield: mantle melting in response to post‐collision extension
Author(s) -
Shumlyanskyy Leonid,
Billström Kjell,
Hawkesworth Chris,
Elming StenÅke
Publication year - 2012
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2012.01075.x
Subject(s) - geology , massif , geochemistry , mantle (geology) , craton , crust , mafic , shield , anorthosite , partial melting , continental crust , petrology , tectonics , plagioclase , seismology , paleontology , quartz
Terra Nova, 24, 373–379, 2012 Abstract The North‐Western region of the Ukrainian shield represents Palaeoproterozoic continental crust formed essentially during two orogenic events at ca. 2.1–2.05 and 2.0–1.95 Ga. At 1.8–1.74 this area was intruded by huge Korosten anorthosite–mangerite–charnockite granite complex. At least three generations of mafic dykes can be distinguished in the region. We report new U‐Pb data obtained for a suite of Ni‐enriched dolerite dykes and layered gabbroic intrusions. Our results indicate that the Tomashgorod dyke was formed at 1787.4 ± 6.4 Ma, the Prutivka intrusion at 1777.0 ± 4.7 Ma and the Kamenka massif at ca. 1.79 Ga. This time coincides with the collision of the Fennoscandian and Sarmatian segments of the East European craton and it is contemporaneous with the initial stages of evolution of the Korosten complex. Hf isotopic compositions of zircons indicate that these rocks originated due to melting of moderately depleted mantle material.