The Emplacement mechanism of Bouin-Miandasht granitoid pluton (Sanandaj- Sirjan zone, West Iran): An application of AMS method

Abstract

Bouin- Miandasht Granitoid Pluton (BMGP), which outcropped to the north of Bouin-Miandasht- Aligoudarz road, was emplaced into low to medium grade of Triassic to early Jurassic metapelitic rocks of Sanandaj-Sirjan Structural Zone. In this study we do provide the first investigations of BMGP by means of anisotropy of magnetic susceptibility (AMS). Most Km values for the main felsic compositions of this pluton are lower than 500 µSI, suggesting it belongs to paramagnetic granites. Felsic part suffered high temperature solid state deformation during emplacement and show magmatic microstructures. The pluton also show low temperature solid state microstructures; which are related to later compressional tectonic regimes. Low plunge magnetic lineations together with low dip foliations defined on the base of magnetic parameters point out that the Bouin- Miandasht granitoid pluton was emplaced as a large sill in a dextral shearing zone related to a transpressional regime.