Origin of plagiogranites and gabbros in the Baft ophiolitic mélange; southwest of Kerman

The Baft ophiolitic mélange, covering an area approximately 150 Km2, is located in the Esfandaghe-Khamrood melange belt. The main part of intrusive rocks in the Baft ophiolitic mélange consists of gabbros, mostly isotropic and occasionally as pegmatitic rocks. Plagiogranites, as veins and small outcrops, are common along with gabbros and doleritic dikes through the area. Plagiogranites consist of trondhjemite, albite granite and granophyre. Based on geochemical studies, gabbros and plagiogranites are belonging to tholeiitic-calc-alkaline magmatic series. Plagiogranites are metaluminous to slightly peraluminous and typologically show characteristics between oceanic ridge (OR) and I-type granites which is consistent with their formation in a supra-subduction zone environment. Chonderite normalized REE patterns of plagiogranites show slight enrichment in LREEs along with flat HREE patterns. Chonderite normalized REE pattern of gabbros are relatively flat with slight enrichment in LREEs compare to HREEs. The derivation of an acidic melt from a gabbroic phase through either fractional crystallization and/or partial melting is less likely. It appears that the origin of Baft ophiolitic melange plagiogranites must be related to doleritic phase, although partial melting of hornblend gabbro and/or amphibolite can be also considered for at least one of the samples.