The age and petrologic and geochemical conditions of formation of the Kogtakh gabbro-monzonite complex in the Kuznetsk Alatau

V. V. Vrublevskii, A. D. Kotel'nikov, A. E. Izokh

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)

Abstract

We present new data on the U-Pb age of zircons, geochemistry of trace elements, and isotope (Nd, Sr, O) composition of rocks of the Kogtakh gabbro-monzonite complex on the eastern slope of the Kuznetsk Alatau Ridge. The established age of zircon in the rocks of the main intrusive phases (500-480 Ma) is taken as the time of formation of the Kogtakh complex in the Late Cambrian-Early Ordovician, during the accretion-collision stage of evolution of the Central Asian Orogenic Belt. The distribution and ratios of LILE and HFSE in the rocks suggest that the intrusions proceeded under interaction of the PREMA + EM/OIB mantle plume and the suprasubductional lithospheric IAB mantle. The mantle-crust interaction led to the heterogeneous isotopic composition of neodymium in the magma source (ɛNd(T) ~ 3.5-5.4). The mixing of different mantle and continental-crust materials resulted in an increase in isotope parameters: (87Sr/86Sr)T ~ 0.7039-0.7052, ɛSr(T) ~ 0-19, and δ18O ~ 6.5-8.8‰ (SMOW). The REE ratio in the least differentiated gabbroids indicates different depths of probable magma chambers and the formation of their primary (Tb/YbPM > 1.8) mafic melts at different degrees of melting of the model garnet peridotite.

Original languageEnglish
Pages (from-to)718-744
Number of pages27
JournalRussian Geology and Geophysics
Volume59
Issue number7
DOIs
Publication statusPublished - 1 Jul 2018

Keywords

  • Central Asian Orogenic Belt
  • crustal contamination
  • garnet peridotite
  • geochemistry
  • geochronology
  • geodynamic setting
  • Kuznetsk Alatau
  • magma genesis
  • mantle plume
  • petrogenesis
  • subalkalic magmatism
  • ALKALINE
  • U-PB
  • MANTLE
  • PB SHRIMP-II
  • TRACE-ELEMENT
  • MAFIC MAGMATISM
  • CENTRAL-ASIA
  • CHEMICAL-COMPOSITION
  • PALEOZOIC GRANITOID BATHOLITHS
  • SM-ND

Fingerprint Dive into the research topics of 'The age and petrologic and geochemical conditions of formation of the Kogtakh gabbro-monzonite complex in the Kuznetsk Alatau'. Together they form a unique fingerprint.

Cite this