نویسندگان
1 دانشگاه لرستان، دانشکده علوم، گروه زمین شناسی
2 گروه زمین شناسی، دانشکده علوم، دانشگاه لرستان
3 گروه زمین شناسی، دانشکده علوم پایه، دانشگاه بیرجند، بیرجند، ایران
4 گروه زمین‌شناسی، دانشکده علوم پایه، دانشگاه شهید چمران اهواز، اهواز، ایران
5 گروه زمین شناسی، دانشکده علوم پایه، دانشگاه لرستان، خرم آباد، ایران
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
The study granitoid pluton is a part of the Mahiroud (Cheshmeh Ostad) volcano-plutonic complex in the southeast of Sarbisheh (South Khorasan province). The composition of this pluton is mostly granodiorite-tonalite. Its main minerals include plagioclase, quartz, orthose and hornblende with granular texture. Based on mineral chemistry, amphiboles in these rocks have a calcic composition and are placed in the Mg-hornblende subgroup. These amphiboles crystallized under pressure conditions of 0.5 to 2 kbar, temperature between 700 - 725 ºC and high oxygen fugacity. Based on the geochemical results, this granitoid pluton is in the range of type I, metalunimous and calc-alkaline granites. Also, this puloton is been formed through mantle partial melting so that La and Dy increase with the increase of La/Sm and Dy/Yb ratios. These rocks were formed through partial melting and less than 5% of sediments have been subducted and fluid has entered the magma source. The spider diagram of trace elements normalized with the primary mantle shows relative enrichment with a gentle slope of LREE elements compared to HREE. This granitoid pluton is similar to subduction-related granites and is consistent with the calc-alkaline magmatic arc in the eastern of Iran which is the result of the subduction of the Neotethys oceanic plate (Sistan Ocean) under the eastern zone of Iran.
کلیدواژه‌ها [English]
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