Publishing House SB RAS:

Publishing House SB RAS:

Address of the Publishing House SB RAS:
Morskoy pr. 2, 630090 Novosibirsk, Russia

Advanced Search

Russian Geology and Geophysics

2009 year, number 1

Paleoarchean tonalite-trondhjemite complex in the northwestern part of the Sharyzhalgai uplift (southwestern Siberian craton): results of U-Pb and Sm-Nd study

O.M. Turkina a,b , N.G. Berezhnaya c , A.N. Larionov c , E.N. Lepekhina c , S.L. Presnyakov c , T.E. Saltykova c
a Institute of Geology and Mineralogy, Siberian Branch of the RAS, 3 prosp. Akad. Koptyuga, Novosibirsk, 630090, Russia
b Novosibirsk State University, 2 ul. Pirogova, Novosibirsk, 630090, Russia
c All-Russian Research Geological Institute, 74 Srednii prosp., St. Petersburg, 199106, Russia
Keywords: Paleoarchean; Siberian craton; Sharyzhalgai uplift; tonalities; trondhjemites; U-Pb age; Sm-Nd isotope geochemistry; petrogenesis
Pages: 15-28


In the northwestern part of the Sharyzhalgai uplift of the Siberian craton (Bulun block), the earliest sialic crust (grey-gneiss complex) is composed of plagiogneisses, their migmatized varieties, and subordinate plagiogranitoids. The petrochemical, trace-element, and Sm-Nd isotope compositions of rocks were studied, and U-Pb dating of zircons (SHRIMP II) was performed. Plagiogneisses and plagiogranitoids of trondhjemite and, more seldom, tonalite compositions are predominant; their compositions are typical of rocks of Archean tonalite-trondhjemite-granodiorite (TTG) complexes (Al2O3 ≥ 15%, Mg# = 28-38, (La/Yb) n = 23-66, Sr/Y = 27-135, Eu/Eu* = 0.7-1.1). Plagiogneisses of meta-andesite-rhyodacite association are subordinate (SiO2 = 59-69%, (La/Yb) n = 7-32, Sr/Y = 11-24, Eu/Eu* = 0.5-0.7). Cathodoluminescent study of zircons revealed