Fluorine impact on the rare earth elements composition of Iranian peraluminous S-type granites

The relation between fluorine (F) content and rare earth elements (REE) concentrations in S-type peraluminous granites have been investigated by chemical analyzing of different rocks from geologically diverse Iranian plutons (Shir-Kuh, Mahneshan, Mashhad, Bornavard and Baneh). These analyses yield informative data about S-type granite petrogenesis. REE-enriched samples have higher F in spite of different petrogenetic evolution in each pluton. Biotite is the most important F-bearing mineral in these rocks controlling F and REE concentrations of peraluminous granites. In a granitic association with F-bearing mineral crystallization, more evolved rocks exhibit notable depletion of REE concentration (biotite granite of Baneh and Shir-Kuh monzogranites). Environmental conditions during partial melting of parental rocks have a key role in the F and REE concentrations of generated granitoids. Granitoid rocks produced by high temperature vapour-absent melting of metasedimentary rocks (Mahneshan and garnet-bearing granites) have low REE relative to granitoids produced by wet, low melting processes.

کلیدواژه ها:

S-type ، peraluminous ، granite ، fluorine ، REE ، biotite