Geochemistry, Age, and Petrogenesis of Rocks
from the Garevka Metamorphic Complex, Yenisey Ridge

I. I. Likhanov and V. V. Reverdatto

Sobolev Institute of Geology and Mineralogy, Siberian Branch, Russian Academy of Sciences,
pr. akademika Koptyuga 3, Novosibirsk, 630090 Russia

e-mail: likh@igm.nsc.ru

Received April 27, 2012; in final form, December 23, 2012

Abstract—The mineralogical, petrological, geochemical and geochronological data on the Garevka metamor-
phic complex (GMC) of the Yenisey Ridge were used to evaluate the age, nature, and provenance of their pro-
toliths. The evolution of the GMC occurred in two stages with different ages, thermodynamic regimes, and
metamorphic field gradients. The final emplacement of granitoids was marked by high-pressure (HP) amphib-
olite facies regional metamorphism (970 Ma). At the second stage, these rocks experienced Late Riphean (900–
870 Ma) retrograde epidote-amphibolite facies metamorphism accompanied by the formation of blastomylo-
nitic complexes within narrow zones of brittle–ductile deformation. The metamorphism of migmatites (850
Ma) is coeval with the collisional medium-pressure metamorphism of the kyanite–sillimanite type. The GMC
is different from the other rock complexes of the Yenisey Ridge in the presence of rapakivi-type granites. The
geochemistry of these rocks, which is characterized by stronger enrichment in K₂O, FeO, Y, Th, U, Zr, Hf, Nb,
Ta, and REE relative to the other mineral assemblages of the GMC, is typical of anorogenic (A-type) within-
plate granites. Among other distinctive features of these rocks are the strong iron enrichment of the melano-
cratic minerals, the presence of ilmenite as the sole Fe–Ti oxide, and crystallization from higher temperature (T
= 825C vs. T = 750C) water-poor magmas under reducing conditions below the FMQ buffer. Significant vari-
ations in the geochemical and petrological characteristics of the GMC rocks suggest that they could not be
derived from a single source. The main volume of the high-K rocks varying in composition from A-type to S-
type granites was generated by melting of mixed mantle–crustal sources. The products of melting of the Late
Archean–Early Proterozoic infracrustal gneisses of the Siberian Craton could be a possible source for the least
oxidized rocks.

Keywords: geochemistry, metamorphism, U–Pb geochronology, metagranitoids, Garevka metamorphic com-
plex, Yenisey Ridge

DOI: 10.1134/S0016702914010042

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