Showing 1 results for Post Collision.
Habib Biabangard, Mohaddesah Rahimzadeh, Abdolreza Pertabian, Ali Ahmadi,
Volume 32, Issue 2 (7-2024)
Abstract
There are acidic to intermediate igneous dykes in the granite and flysch zones at the south of Zahedan,
Based on geological classification of Iran, they are belong to the Sistan Suture zone (SSZ). These dykes have different trends but usually northwest-southeast trend, with a several kilometers at the length and an average five meters the width. They are usually folding and often have sharp border with the host rocks, and a lot of to different make of metamorphosed surrounding rocks. They are mainly diorite to granodiorite and similar extrusive in composition, and have been formed of mainly Plagioclase, biotite, hornblende and varying amounts of quartz minerals. These dyke have usually Porphyry to microgranular textures. Based on geochemical data they are calk-alkaline, high potassium calk-alkaline and meta-aluminous to peraluminous. They are enrichment from Zr, Rb, Sr, Br elements and depleted from V, Ni, Co elements compared to Chondrite references. These dykes are enriched from light rare earth element (LREE) to High rare earth elements (HREE), compared to Chondrite and primitive mantle. Eu/Eu* ratio changes between 0.99-1.2. Tectonomagmic and petrogenesis diagrams shows that they are belonging to subduction and late post collision zones. They have an amphibolite sources and geochemically formation similar to Zahedan granitoid environment. Therefore, it seems that the magma forming these dykes, similar to the Zahedan granite, was formed from the mantle wedge above the subduction plate of the Neotethys ocean under Central Iran plate after to shortly after the collision.
