Metamorphosed mantle peridotites from Central Iran (Jandaq area, Isfahan province)

$39.00 plus tax (Refund Policy)

Buy Article:

Abstract:

Mantle peridotites of the Jandaq ophiolite are composed of metamorphosed lherzolite and harzburgite, with lherzolitic mineralogical and bulk chemical compositions prevailing over harzburgite. They are closely associated and isofacial with amphibolites and Paleozoic metasedimentary rocks (schist and marble). Rock forming minerals of metalherzolites are clinopyroxene, Cr-spinel, olivine, tremolite, chlorite, serpentine, magnetite and calcite. Metaharzburgites are composed of olivine, orthopyroxene, talc, anthophyllite, magnetite, Cr-spinel ± low amounts of chlorite and tremolite. The olivine and orthopyroxene in these rocks are metamorphic products, not relicts of the primary igneous mineralogy. Early relict phases (mantle phases) include clinopyroxene and Cr-spinel. Petrography, mineral chemistry, as well as major and trace element geochemistry of the metamorphic lherzolites indicate that they are relicts of undepleted mantle material and have experienced less than 3% partial melting. Metamorphic assemblages in metaperidotites, mineral chemical studies, together with additional geological constraints, indicate that the Jandaq mantle peridotites are metamorphosed under upper amphibolite facies conditions (8 to 9 kbars and 714 to 737 °C), followed by a retrograde metamorphism under greenschist facies conditions. The maximum temperature of regional metamorphism was not sufficient to replace calcic amphibole (tremolite) by calcic pyroxene. Textures (magnetite inclusions in metamorphic olivines) and associated rock types (meta-listwaenite) indicate the studied rocks were partly altered (M1) before being progressively metamorphosed under upper amphibolite facies conditions (M2). Late-stage retrograde metamorphism (M3) led to formation of chlorite and thin irregular serpentine veinlets, partially to serpentinization of metamorphic olivine and orthopyroxene, and partial replacement of chromian spinel by ferritchromite and magnetite. These three metamorphic episodes can be attributed to the Early, Middle and Late Cimmerian orogenies of Iran, respectively.

Keywords: CENTRAL IRAN; JANDAQ; LHERZOLITE; MANTLE PERIDOTITE; METAMORPHISM; OPHIOLITE

Document Type: Research Article

DOI: http://dx.doi.org/10.1127/0077-7749/2011/0153

Publication date: August 1, 2011

More about this publication?
  • Neues Jahrbuch für Geologie und Paläontologie continuously publishes current original contributions from all fields of geology, ever since its foundation in 1807. All published contributions are in the English language.
  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • ingentaconnect is not responsible for the content or availability of external websites
Related content

Tools

Favourites

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more