| Popis: |
The studied area is located in the south to east of the Qorveh (Majidabad and Kangareh; Kurdistan Province) in the Sanandaj-Sirjan zone. Based on field survey, the dykes are gabrroic to gabbro-norite rocks in composition, and followed by granites dykes with low abundances and they have intruded in the granitoid rocks. The most abundance dykes are diorites (monzodioritic and quartz-monzodioritic rocks). They consist of plagioclase (An54.87–45.95), pyroxene (Wo32.92–50.77 En36.28–40.55 Fs8.67–27.89), hornblende and sometimes K-feldspar and quartz. The mafic rocks include plagioclase (An66.28–58.72), clinopyroxene, orthopyroxene and hornblende which based on mineralogy and geochemical classification are divided to two groups: gabbroic and gabbro-noritic rocks. Biotite, apatite, titanite, zircon and opaque minerals are their accessory minerals in both of group. Microscopic studies and microprobe analyses data show amphiboles and biotites are Mg-hornblende and annite, in composition, respectively. The mafic rocks have tholeiitic-calc-alkaline affinity. Spider diagrams imply enrichment in LILE (such as Cs, Rb, U and Pb), depletion in HFSE (Nb and Ba) and high LILE/HFSE ratio. The enrichment in LILE and Pb suggest the crustal contamination. The tectonic setting discrimination diagrams reveal all of rocks belong to volcanic arc related to an active continental margin setting. |
