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The Alvand plutonic complex is located in NW of the Sanandaj-Sirjan metamorphic belt. It comprises mafic, intermediate, and felsic rocks with different ages. The following conclusions are based on comprehensive field and petrographical studies in this complex and surronding metamorphic rocks. This plutonic complex is composed of variety of lithologies from melanocratic to hololeucocratic rocks. The mafic and intermediaate plutonic rocks show petrographical and geochemical genetic relationship. They consist of olivinegabbro, gabbronorite, dolerite, diorite, quartz-diorite and tonalitic rocks. The prophyroid granites are composed of monzogranites, granodiorites, and minor syenogranites and alkali feldspar granites. In these rocks biotite is essential mafic mineral and another mafic minerals are absent. Holoeucocratic granitoids are composed of leucotonalites, leucograno-diorites, leuco-quartzdiorites and leuco-quartz monzodiorites. In these rocks mafic minerals such as biotite, sphene, and rutile are rare.
Field relationship indicates plutonism in the Alvand complex have occrred in several stages. Plutonic phases show sharp contacts indicating that each phase were intruded after solidification of previous phases. Repeated intrusion of several magma batches produced an extensive magmatic breccia as Alvand plutonic complex. The sequence of intrusion are followed respectively, gabbro-diorites and tonalites, fine grained porphyroid granites, coarse grained porphyroid granites, porphyroid hololeucocratic granitoides, fine grained holoeucocratic granitoids, porphyroid holoeucocratic granitoides. Porphyroid grainites (monzogranites) which comprise essential part of the plutonic complex have been intruded in two stages: the first stage is the intrusion of the fine granied phase and the second one is coarse grained porphyroid granites. Both phases show many restites and surmicaceous enclaves and xenocrysts of andalusite, sillimanite and garnet and therefore they probably have crustal (anatectic) origin.
Holoeucocratic granitoids have been intruded in two stages: the first phase is porphyroid holoeucocratic granitolds and the seccond one is fine grained. Silicic veins result from anatectic fluids or residual liquids of crystalized magmas.