South Kiki granitoid intrusion is located north of Semnan Province, about 5 km south of the village of Kiki. This pluton emplaced wholly within the Jurassic sandstones with typical contact
metamorphic aureole around their periphery. The plutonic rocks suffered high-temperature deformation with well-developed S-C
fabrics along shear zones
marginal to the intrusion. The pluton was subjected to intensive plastic deformation in the contact so that the deformation gradually decreases with increasing distance from margins toward the inner side of the pluton. Due to high-temperature deformation, some of primary magmatic minerals such as plagioclase and orthoclase were broken and were filled again by some high-temperature magmatic minerals such as biotite, potassium feldspar and quartz. Based on the following evidences, it seems that the deformation happened during the emplacement of the pluton Just above the solidus temperature and possibly in presence of a small amount of molten: 1) Filling fractures of primitive feldspar crystals by sets of fine grain quartz, potassium feldspar and biotite (Sub-magmatic structure), and also transforming of monoclinic orthoclase
to microcline at high stress rates which led to formation of the orthoclase lenses. 2) Presence of quartz and feldspar grains within the deformed cleavages of biotite and bending of the biotite cleavages to smaller chlorite assemblage at higher deformation. 3) Quartz and potassium feldspar intergrowth partially replaced plagioclase and also kink band and submagmatic structure occur in the plagioclase crystals. 4) Existence of the undeformed granophyric textures in the margin of deformed orthoclase crystals. 5) Individual crystals of quartz normally show undulose extinction and recrystallization.