New data on the composition and age of granitoids in the northern part of the Tagil structure (Ural Mountains)

摘要

The Tagil structure representing a large fragment of the Paleozoic island arc on the eastern slope of the Urals has been sufficiently well studied in its southern part (Middle Urals). In contrast, reliable data on the age and geochemical properties of various, including granitoid, rock complexes available for its northern part are scarce. The first data on the U-Pb LA-ICP-MS age of zircons from quartz diorites of the Man'ya massif of the Petropavlovsk Complex (436 +/- 3 Ma, MSWD = 1.3), tonalites of the same complex (439.4 +/- 1.3 Ma, MSWD = 1.3), granites of the Yuzhno-Pomur massif of the Severorudnichnyi Complex (422.4 +/- 3 Ma, MSWD = 1.5), and titanite of the same massif (423.4 +/- 4.4 Ma, MSWD = 0.84) have been obtained. Based on these data combined with the geochemical properties of the host rocks, the conclusion that they were crystallized at the initial stages of the formation of comagmatic volcanic series is supported; by their composition, granitoids correspond to island arc igneous rocks.