Литосфера (Oct 2016)

Plagioclasites from chromite-bearing ultramafic rocks of the Rai-Iz massif

  • N. V. Vakhrusheva,
  • K. S. Ivanov,
  • A. E. Stepanov,
  • S. P. Shokalsky,
  • A. N. Azanov,
  • V. V. Hiller,
  • P. B. Shiryayev

Journal volume & issue
Vol. 0, no. 5
pp. 134 – 145

Abstract

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The corundum-bearing and without-corundum plagioclasites from chromite-bearing ultramafic rocks of Rai-Iz massif were studied. Chemical composition of the rock-forming minerals and rock geochemical characteristics was determined. The U-Pb zircon dating (using SHRIMP-II microprobe) of plagioclasites yielded an age of 398 ± 3 and 404.4 ± 2.8 Ma - Lower-Middle Devonian boundary. At that time on the background of powerful collision it occurred a deep metamorphic processing of Rai-Iz ultramafic rocks resulting in forming of high-chromium chromite ore and separation of vein-series represented by substantially plagioclase rocks with corundum (ruby) mineralization.

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