جستجوی مقالات مرتبط با کلیدواژه "خاستگاه پریدوتیتی" در نشریات گروه "زمین شناسی"

In the southeastern edge of the Pedaran village, about 40 km southeast of Birjand, basalt masses containing olivine phenocrysts and fine-grained groundmass, consisting of pyroxene, plagioclase and opaque minerals, are exposed. Based on the X-ray microprobe analysis, the olivine mineral has composition of Fo75-87 Fa13-25 and chrysolite. Ni/Mg and Mn/Fe ratios in olivine indicated that the formative melt of Pedaran basalt lie in the peridotitic source. Based on the geochemical characteristics of major elements, these rocks are alkaline (close to sub-alkaline). High field strength elements (HFSE), such as Nb, P, Zr and Ti, show negative anomalies, which indicated these rocks are related to subduction zones. The magma that formed the Pedaran basalts, originated from the transition zone between spinel and garnet lherzolite at a depth of about 70 km. Discrimination diagrams of the tectonic environment using trace elements showed that the samples are ploted in the calc-alkaline range and belong to the continental arc.