Deformation Microstructures in Plagioclases of the Doran Granite: An Interpretation to Emplacement of this Intrusion at the Type Locality, Zanjan

Abstract

Observations on the microstructure of a rock, in thin section, can be used to reconstruct its tectonic evolution. This paper presents deformation microstructures, which were observed in Plagioclase of the late precambrian Doran-granite at the type locality in south of Zanjan. Two sample-sets of central and marginal parts of the Doran intrusion show similar microstructures, which can be related to temperatures up to 500°C, believed as emplacement temperature of the Doran intrusion in shale of Kahar-formation. The former structures are affected, in some samples of marginal part of the intrusion, by cataclastic flow, formed at temperatures lower than 400°C, during subsequent uplift. The good preservation of the deformation microstructures, in the studied samples, can be referred to fast decrease of temperature, meaning quickly uplift process. Microscopic deformation-induced microstructures of minerals in rocks and set the conditions for reconstruction at the time of adoption of intrusive form used in the study, because the microstructure formation in minerals affected by the different conditions of temperature and pressure, and can be different stages of the fit mass to reflect stones. In this paper, the microscopic induced deformation microstructures in plagioclase White granite outcrop in the model presented, the analysis is presented on how to fit the masses.