THE PETROLOGY AND GEOCHRONOLOGY OF GRANITES FROM LISKI PLUTON, VORONEZH CRYSTALLINE MASSIF
Liski pluton was emplaced as two-phase ring-shaped pluton involved (1) the first phase consists of fine-grained in the chilled zone to coarse-grained porphyritic in the center leucomontzogranites, (2) the second phase is represented by micrographic leucogranodiorites, leucomonzo- and leucosienogranites. Liski granites display the typical geochemical characteristics of A-type granites, namely high SiO2, Na2O + K2O, FeO*/MgO, TiO2/MgO, and F and low CaO and MgO. They have extreme liquidus temperatures (870±18 °С) and are rich in characteristic accessory minerals including xenotime, tantalum-niobates, fluor spar. The granosyenites/granodiorutes of Pavlovo comlex and leucogranites of Bobrov complex has a chemical composition different from the Liski granites. It displays calc-alkaline characteristics. Liski pluton belongs to the youngest stage of Paleoproterozoic igneous activity (2064±14 Ma) in the Don terrane that triggered in emplacement of the hypabyssal intrusion. Age of host rocks of the Don terrane corresponds to Neoarchean (~2,6 Ga). The Liski granites display the general characteristics of A-type rocks and their structure and chemistry are consistent with a post-collisional setting.