Study of composition, source and tectonic setting of metapelite rocks from Mahneshan complex, NW, Iran

Geotechnical Geology

دوره 4، شماره 2، مرداد 2008، صفحه 133-143   

نوع مقاله: Original Research

نویسندگان

Adel Saki^{* 1}؛ Gholamreza Mirzavand²

¹Department of Geology, Faculty of Earth Science, Shahid Chamran University Ahvaz, Ahvaz, Iran

²Department of Geology, Faculty of Science, Islamic Azad University - Dezful Branch, Dezful, Iran

چکیده

The Precambrian rocks of Mahneshan Complex in Northwestern Iran were affected by regional and contact metamorphism. At the Mahneshan Complex different types of igneous and metamorphic rocks are exposed. Metamorphic rocks including metapelites, amphibolites, metavolcanite, para-gneiss, metaperidotites and serpentinites. Metapelites are foliated at two directions. Exact petrographic and petrofabric studies on them show that three metamorphic phases including two regional and one contact are affected the rocks. Andalusite, staurolite, kyanite and garnet minerals are crystallized during second regional metamorphic phase. Geochemistry studies of metapelites shows that, Composition of old meta-sedimentary rocks (source of metapelites), are shale and greywacke. Discrimination diagrams indicate an arc related tectonic setting for the source of Mahneshan metapelites. Sources of Mahneshan metapelites are intermediate felsic igneous rocks (rhyolite or andesite) base on Geochemistry of immobile elements.

کلیدواژه‌ها

Discrimination diagrams؛ Mahneshan complex؛ Metapelites؛ Shale