Metacarbonate-terrigenous complex of the Derba block (East Sayan): petrogeochemical and isotope parameters, metamorphism, and time of formation

A. D. Nozhkin, O. M. Turkina, N. V. Dmitrieva, A. V. Travin, I. I. Likhanov

Research output: Contribution to journalArticlepeer-review

Abstract

The Derba block is one of the largest Precambrian terranes of the Sayan-Yenisei accretionary belt in the southwestern margin of the Siberian Platform. It is composed of metamorphosed terrigenous-carbonate rocks of the Sayan Group, injected by granitoids. The geochemical features of gneiss-schist associations indicate the low maturity of their sedimentary protoliths corresponding in composition mainly to graywackes and terrigenous-carbonate rocks (marls). According to the results of U-Pb (LA-ICP-MS) dating of detrital zircons from gneisses and schists, the sedimentary protolith formed in the Vendian. Neoproterozoic subduction complexes were probably the major provenance for terrigenous material, and Early Precambrian rocks made a limited contribution. The Ar-Ar and U-Pb isotope data testify to nearly coeval and multistage events of metamorphism (up to the amphibolite facies) and granitoid magmatism (~ 510-500 and 480-465 Ma) in the Derba block. These processes were reflective of the Early Caledonian orogenic processes in the structures of the Central Asian Orogenic Belt. The similarity in the composition, time of sedimentation, and provenances of metaterrigenous-carbonate complexes of the Derba block (Sayan Group), West Sangilen block of the Tuva-Mongolian massif (Erzin and Moren complexes), and the Khamar-Daban terrane (Slyudyanka Group) suggests that these structures were a single Vendian continental margin with lateral variations in depositional environments and the sources of terrigenous material.

Original languageEnglish
Pages (from-to)652-672
Number of pages21
JournalRussian Geology and Geophysics
Volume59
Issue number6
DOIs
Publication statusPublished - 1 Jun 2018

Keywords

  • Derba block
  • geochemistry
  • metamorphism
  • terrigenous carbonate rocks
  • U-Pb (LA-ICP-MS) and Ar-Ar dating
  • SOUTHWESTERN MARGIN
  • OLKHON REGION
  • U-PB
  • WESTERN MARGIN
  • EVOLUTION
  • MONGOLIAN MASSIF
  • ACCRETION
  • SIBERIAN CRATON
  • GEOCHEMISTRY
  • AGE

Fingerprint

Dive into the research topics of 'Metacarbonate-terrigenous complex of the Derba block (East Sayan): petrogeochemical and isotope parameters, metamorphism, and time of formation'. Together they form a unique fingerprint.

Cite this