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Petrography, Mineralogy and Thermodynamic Modeling of Eclogites from the Serkout Area, Central Hoggar, Algeria

  • Doukkari SidaliEmail author
  • Godard Gaston
  • Ouzegane Khadidja
  • Arab Amar
  • Bendaoud Abderrahmane
Chapter
Part of the Advances in Science, Technology & Innovation book series (ASTI)

Abstract

The Aleksod terrane Eclogites, sited in the Central Hoggar, preserve a selection of eclogite-facies assemblage (coarse garnet, omphacite, quartz, clinozoisite and amphibole). During retrogression, these minerals were partially substituted with coronas and symplectites of diopside-plagioclase and amphibole-plagioclase. The almandine-dominated garnet proves to enclose heterogeneous compositions (XAlm0.30–0.56). The omphacite displays a high XJd of 0.31. The eclogite-facies coarse amphibole is magnesio-hornblende with NaM4 = 0.31–0.47. The plagioclase is usually secondary exhibiting a range of composition from oligoclase to anorthite (XAn = 0.20–0.99), where albite-rich and anorthite-rich compositions prove to correspond, respectively, to symplectite after omphacite and coronas around epidote. The relevant P-T pseudosections using THERMOCALC-340 are calculated to estimate peak conditions and trace the P-T evolution. At H2O-saturated conditions, inclusions of amphibole in garnet core with garnet composition from core to inner rim are used to trace pre-peak P-T path from 14 kbar–610 °C to 18 kbar–700 °C. At H2O-undersaturated conditions, the retrograde path has been traced using secondary phases as plagioclase, diopside and amphibole at 10 kbar–720 °C.

Keywords

Eclogite Serkout Hoggar Thermodynamic modeling P-T path 

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Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  • Doukkari Sidali
    • 1
    Email author
  • Godard Gaston
    • 2
  • Ouzegane Khadidja
    • 1
  • Arab Amar
    • 1
  • Bendaoud Abderrahmane
    • 1
  1. 1.LGGIP, FSTGAT, U.S.T.H.B.AlgiersAlgeria
  2. 2.IPGP. 1Paris Cedex 05France

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