Petrogenesis of adakitic and calc-alkaline granitoids in Rabor-Lalehzar region, SE of Kerman: Constraints from geochemical and Sr-Nd isotopes results

Study area located on N to NW of Rabor city in Kerman province that belong to Uromieh-Dokhtar Magmatic Belt (UDMB). Most of rock lithology in this area including diorite, granodiorite and granite which have been exposed in volcanic sequences. Based on geochemical studies all of rocks in this area classified in two groups: (1) some igneous rocks show adakitic affinity with high SiO2 (61.49–66.78 wt. %), Al2O3 (15.72–17.74 wt. %), Sr (374–602 ppm), Sr/Y (34–53), (La/Yb) N (8.35–16.88) and low Y values. (2) another rock group that distinguished in study area including various granitiods rocks with typical calc-alkaline characteristics that distinct from adakitic types such as: SiO2 (63.07–72.32 wt. %), lower Sr/Y (3.8–13.2) ratio and higher Y (21.7–31.6 ppm) and Yb (2.29–3.26 ppm) contents, and the lowest Sr (119–297 ppm) and (La/Yb)N (3.02–11.13) values relative to adakitic groups, with distinctly negative Eu [(Eu/Eu*)N= (ave. 0.49)] anomalies.The adakitic rocks most probably originated from thickened mafic lower crust (garnet amphibolite) with garnet rutile ± plagioclase as residual minerals in the source corresponding to depths of >50 km, and calc-alkaline rocks were probably generated in shallow depth than adakitic groups in mid-lower crust (dominant amphibolite) correlating to depths of