The mylonitic granites exposed in the central part of the Sanandaj–Sirjan Zone (CSSZ) are emplaced into the Precambrian basement along the Main Zagros Fault. U–Pb zircon dating of their protolith yields an emplacement age of 297.8 ± 3.9 Ma (Early Permian), consistent with emplacement in a within-plate extensional tectonic setting. The mylonitic granites are classified as transitional A-type, characterised by enrichment of High Field Strength Elements (HFSE) and elevated Nb/Y and Ga/Al ratios. Trace-element systematics, particularly variations in Nb, Hf, Ta, and Zr, indicate a magmatic origin involving significant magma–crust interaction. The εNd_(t) values are around 0.9. The isotopic compositions likely reflect post-magmatic disturbance, and the mylonitic granites were later transformed into mylonitic varieties during Mesozoic tectono-thermal reactivation along regional shear zones. Petrographic evidence, including perthitic K-feldspar, well-developed gneissic banding, and advanced dynamic recrystallisation textures, indicates that the Azna mylonitic granites experienced intense dynamic metamorphism. Now, this deformation resulted in partial resetting under lower greenschist-facies conditions within a brittle–ductile regime. Accordingly, the primary crystalli­sation of the protolith of the Azna mylonitic granite most likely occurred during the late stages of the Variscan orogeny and, within the framework of the proposed model, can be interpreted as being associated with the onset of processes leading to the opening of the Neo-Tethys.