title: Petrographic and petrogeochemical features of harzburgites and dunites of the Agardag and Ulor massifs (South-Eastern Tyva)
metadata.name: dc.contributor.author
metadata.value: Peshkov, Alexey A.
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Chernyshov, Alexey I.
metadata.lang: -
metadata.name: dc.date.accessioned
metadata.value: 2021-08-20T19:13:55Z
metadata.lang: -
metadata.name: dc.date.available
metadata.value: 2021-08-20T19:13:55Z
metadata.lang: -
metadata.name: dc.date.issued
metadata.value: 2021-06
metadata.lang: -
metadata.name: dc.identifier.citation
metadata.value: Peshkov, A. A., Chernyshov, A. I. (2021). Petrographic and petrogeochemical features of harzburgites and dunites of the Agardag and Ulor massifs (South-Eastern Tyva). Vestnik of Saint Petersburg University. Earth Sciences, 66 (2), 331–348.
metadata.lang: en_GB
metadata.name: dc.identifier.other
metadata.value: https://doi.org/10.21638/spbu07.2021.208
metadata.lang: -
metadata.name: dc.identifier.uri
metadata.value: http://hdl.handle.net/11701/32807
metadata.lang: -
metadata.name: dc.description.abstract
metadata.value: The objects of study are the Agardag and Ulor ultramafic massifs, which are part of the South
  Tuva ophiolite belt. The aim of this work is to study the petrographic, petrochemical and
  geochemical features of harzburgites and dunites of the studied massifs. As a result of petrographic
  study, the main types of rocks that make up the studied massifs were identified.
  Harzburgites predominate in the Agardag massif, while dunites are more common in the
  Ulor massif. In the Ulor massif, dunites and harzburgites are often plastically deformed by
  syntectonic recrystallization with the formation of porphyroclastic structures. The chemical
  compositions of olivine and Cr-spinels in harzburgites and dunites in both massifs are similar.
  The composition of olivine corresponds to forsterite, while the ultramafic rocks of the Ulor
  massif show large variations in Fa and a tendency towards a decrease in NiO. Chromium
  spinels in ultramafic rocks of the Ulor massif have wider compositional variations and are
  represented by chromites, alumochromite and subferrial alumochromite; they are completely
  free of V2O5. According to the composition of Cr-spinels, the degree of melting of ultramafic
  rocks was determined, which turned out to be similar for both massifs, ~40–50%. A higher
  chromium content of the ultramafic rocks of the Agardag massif is noted, which is probably
  responsible for its increased potential chromite content. Ultramafic rocks of the Agardag and
  Ulor massifs are intensely depleted formations that arose in similar conditions, which determines
  the closeness of their rock and material compositions. The revealed differences are due
  to variations in the degree of depletion and the conditions of their consolidation in the earth’s
  crust, determined by the structural position, as well as metamorphism of the enclosing frame
  and the introduction of later intrusions.
metadata.lang: en_GB
metadata.name: dc.description.sponsorship
metadata.value: The study was carried out within the framework of a grant under the Decree of the Government of
  the Russian Federation dated 09.04.2010 No. 220 under an agreement with the Ministry of Education and
  Science of the Russian Federation No. 14.Y26.31.0012 dated 20.02.2017.
metadata.lang: en_GB
metadata.name: dc.language.iso
metadata.value: ru
metadata.lang: en_GB
metadata.name: dc.publisher
metadata.value: St Petersburg State University
metadata.lang: en_GB
metadata.name: dc.relation.ispartofseries
metadata.value: Vestnik of St Petersburg University. Earth Sciences;Volume 66; Issue 2
metadata.lang: -
metadata.name: dc.subject
metadata.value: ophiolites
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: ultramafic rocks
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: petrography
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: harzburgites
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: dunites
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: petrochemistry
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: geochemistry
metadata.lang: en_GB
metadata.name: dc.title
metadata.value: Petrographic and petrogeochemical features of harzburgites and dunites of the Agardag and Ulor massifs (South-Eastern Tyva)
metadata.lang: en_GB
metadata.name: dc.type
metadata.value: Article
metadata.lang: en_GB
resources.filename: 331-348.pdf
resources.url: https://dspace.spbu.ru/bitstream/11701/32807/1/331-348.pdf
resources.format: Adobe PDF
resources.size: 2,16 MB