Petrography, mineral chemistry and origin of lamprophyric dykes from Sareashk Village, South West of Ravar- Kerman

At 60km north-east of Kerman city,near Sarashk village (Ravar, Kerman province) and along the Kuhbanan fault, several lamprophyric dikes have been intruded into Carboniferous to Cretaceous sedimentary formations. Petrographically these lamprophyres could be classified into two  groups: comptonites and sanaite. Olivine, clinopyroxene, plagioclase and potassium feldspar are the main minerals in all two groups. Mineral chemistry shows that olivines, clinopyroxenes and amphiboles are of chrysolite (Fo = 72.35-79.85)), augite (Wo = 44.3-50.2, En=  37.06-44.4, Fs = 9.24-14.6), and  kaersutite (Ca+Na = 2), (Na+K = 0.59-0.95), (Mg/(Mg+Fe2) = 0.63-0.76) composition, respecrively. Geobarometric and geothermometric estimations along with the tectonomagmatic diagrams for clinopyroxenes show that the parental magmas werealkaline in which the clinopyroxenes crystallized at pressure of 11-15 Kbar and temperature of 1150-1300 ◦C.Whole rock chemical analyses of these rocks show that the parental alkaline magma was originated from a metasomatized lithospheric garnet- spinel- lherzolite mantle source and emplaced in a post-collisional environment.