title: Synrift deposits of the Middle Riphean Mashak Formation, Southern Urals (a short lithochemical characterization)
metadata.name: dc.contributor.author
metadata.value: Maslov, Andrey V.
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Gareev, Emir Z.
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Podkovyrov, Victor N.
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Kovalev, Sergey G.
metadata.lang: -
metadata.name: dc.contributor.author
metadata.value: Kotova, Ludmila N.
metadata.lang: -
metadata.name: dc.date.accessioned
metadata.value: 2018-10-23T15:22:23Z
metadata.lang: -
metadata.name: dc.date.available
metadata.value: 2018-10-23T15:22:23Z
metadata.lang: -
metadata.name: dc.date.issued
metadata.value: 2018-09
metadata.lang: -
metadata.name: dc.identifier.citation
metadata.value: Maslov A. V., Gareev E. Z., Podkovyrov V. N., Kovalev S. G., Kotova L. N. Synrift deposits of the Middle Riphean Mashak Formation, Southern Urals (a short lithochemical characterization). Vestnik of Saint Petersburg University. Earth Sciences, 2018, vol. 63, issue 3, pp. 303–325.
metadata.lang: en_GB
metadata.name: dc.identifier.other
metadata.value: 10.21638/spbu07.2018.304
metadata.lang: -
metadata.name: dc.identifier.uri
metadata.value: http://hdl.handle.net/11701/14975
metadata.lang: -
metadata.name: dc.description.abstract
metadata.value: The article briefly describes the lithochemical features of sandstones and clayey rocks of
  Mashak Formation (Southern Urals), a second synrift volcano-sedimentary association in
  Riphean stratotype. It is shown that the sandstones of the Mashak Formation are characterised
  by wide variations in the bulk chemical composition (from greywacke to quartz arenite).
  The presence of the latter, as well as a relatively small proportion of arkoses and subarkoses,
  distinguishes the second synrift association from the first one (the Ai Formation, Lower
  Riphean). There is no overlap in between the Mashak’s and Ai’s psammites on the diagram
  log(SiO2/Al2O3)–log(Na2O/K2O) of F. J. Pettijon and co-authors. It indicates significant differences
  in provenances and common features of accumulation of the Mashak and Ai formations.
  On the basis of bulk chemical composition, the clayey rocks of the Mashak Formation
  are related to smectite (with kaolinite and illite admixture) clays and their chlorite-smectiteillite
  varieties. The clayey rocks of the Ai Formation differ by lower values of total normative
  alkalinity (0.27 ± 0.06 vs. 0.42 ± 0.07). It is established that sandstones and clayey rocks of the
  Mashak Formation contain a significant proportion of the “first-cycle material”, i. e. they are
  composed mainly by products that have passed one sedimentation cycle. As opposite, there
  is a significant proportion of “second-cycle/lithogenic material” of the first synrift sandstones association (the Ai Formation). The high K2O/Na2O values, which are characterised for a half
  studied samples of the Mashak Formation, indicate that they were influenced by processes of
  potassium metasomatism. The distribution of data points of terrigenous rock of the Mashak
  Formation on diagram F1—F2 (Roser and Korsch, 1988) displays that they are composed by
  products of erosion of acid, average or mafic igneous and/or metamorphic rocks. The individual
  data points of Mashak Formation terrigenous rocks, as well as sandstone composition
  midpoint, are localised in the areas of riftogenic and collisional settings on the DF1—DF2
  diagram (Verma and Armstrong-Altrin, 2013). It does not allow us to define their paleogeodynamic
  settings. In such a manner, the a critical role, traditionally, remains on general geological
  data and petrogeochemical characteristics of igneous rocks.
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 63; Issue 3
metadata.lang: -
metadata.name: dc.subject
metadata.value: Southern Urals
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: Middle Riphean
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: Mashak Formation
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: sandstones
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: clay rocks
metadata.lang: en_GB
metadata.name: dc.subject
metadata.value: lithochemistry
metadata.lang: en_GB
metadata.name: dc.title
metadata.value: Synrift deposits of the Middle Riphean Mashak Formation, Southern Urals (a short lithochemical characterization)
metadata.lang: en_GB
metadata.name: dc.type
metadata.value: Article
metadata.lang: en_GB
resources.filename: 04-Maslov.pdf
resources.url: https://dspace.spbu.ru/bitstream/11701/14975/1/04-Maslov.pdf
resources.format: Adobe PDF
resources.size: 2,86 MB