A1 Refereed original research article in a scientific journal

Geochemical and Characteristics of Mafic and Ultramafic Rocks of the Suprasubduction Zone Mawat Ophiolite, NE Iraq




AuthorsAl Humadi Heider S, Väisänen Markku, Ismail Sabah A

PublisherUnion of Iraqi Geologists

Publishing placeBagdad

Publication year2022

JournalIraqi Geological Journal

Volume55

Issue2F

First page 16

Last page42

eISSN2663-8754

DOIhttps://doi.org/10.46717/igj.55.2F.2ms-2022-12-17

Web address https://igj-iraq.org/igj/index.php/igj/article/view/1152/1115


Abstract

New geochemical data were presented for the mafic (basalts and gabbros) and ultramafic (dunites, serpentinites and pyroxenites) rocks from the Mawat ophiolite exposed in the Zagros suture zone in northeastern Iraq. The mantle section of the ophiolite is composed of serpentinized peridotites, harzburgites, dunites, chromitites and pyroxenite dykes. The crustal section is composed of layered amphibole-rich gabbros, pegmatitic gabbros as well as basalts and minor felsic dykes. The ultramafic rocks are highly depleted in the LILEs and most of the HFSEs. The mafic rocks are tholeiitic, characterized by depletion of LREEs and display a positive trend from LREE to HREE with low Ti/V ratios. The younger gabbros are mostly calc-alkaline, characterized by enrichments of LREE with a negative REE trend and high Ti/V ratios. The basaltic and ultramafic samples plot below the N-MORB reference line suggesting that these elements have been mobile. They fall within the boninitic field in the Ti/V diagram and are related to the subduction initiation setting. The younger gabbros are related to rifting which postdated the formation of ophiolite. These geochemical data are consistent with the subduction-related suprasubduction zone tectonic setting.



Last updated on 2024-26-11 at 11:04