Paleoproterozoic Age of Gneiss-Granites of the Mamskaya Zone (Baikal-Patom Belt): Geological Implications

This article presents the results of U-Pb geochronological study of gneiss-granites of the Mamskaya zone. The age estimate of 1874 +/- 9 Ma (SIMS method) obtained for the magmatic protolith of gneiss-granites for the first time proves the close formation time of gneiss-granites from the Mamskaya zone and rapakivi-like granites of the Kodar complex in the Chara-Olekma block. In the Late Devonian and Carboniferous, according to preliminary data, the Paleoproterozoic protolith of the gneiss-granites underwent deep metamorphic processing during shear deformations and formation of pegmatoid granites and pegmatites.

Automated summary

The study reveals a close relationship in the formation time between gneiss-granites of the Mamskaya zone and rapakivi-like granites of the Kodar complex, with the Paleoproterozoic protolith of the gneiss-granites undergoing deep metamorphic processing in the Late Devonian and Carboniferous periods.