Using mineral chemistry in determining the formation conditions and tectonic setting of Dalfard quartz-diorites (northwest of Jiroft-Kerman Province)

Dalfard granitoid complex is located in the southeast of Kerman Province between  57˚ 30 ˊ to 57° 45 longitudes and 28˚ 55ˊ to 29˚ 10 ˊ latitudes. This granitoide complex contains granite, granodiorite, quartz-diorite, diorite, in the margins, and is mainly composed of quartz-diorite. The main texture is granular and include quartz, plagioclase, amphibole, biotite and alkali-feldspar, with some mafic microgranular enclaves in them. The EMPA data showed that plagioclase are andesine and alkali-feldspar with orthoclase composition. Biotites with Fe/Fe+Mg > 3.3 rato fall in the magnesium-rich biotites area. Amphiboles are calcium type and they have magnesiohornblende in composition, which indicates that their host magmas are I-type. The low values of Na2O in amphiboles, their calc-alkaline nature, and the high oxygen fugacity indicate that they belong to the subduction environment and mantle derived magmas along with the crustal compounds contributed to the formation of their host magmas. Geo-thermo-barometry calculations estimate the average crystallization pressure of 1.4 kb and temperature of 681 °C for the studied hornblende.