Fatemeh Najmi; Azadeh Malekzadeh Shafaroudi; mohammad Hassan Karimpour
Abstract
The North of Baharieh prospecting area is located central part of Khaf-Kashmar-Bardaskan magmatic belt (KKBMB), east of Kashmar in Khorasan Razavi province. This area includes outcrops ...
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The North of Baharieh prospecting area is located central part of Khaf-Kashmar-Bardaskan magmatic belt (KKBMB), east of Kashmar in Khorasan Razavi province. This area includes outcrops of pyroclastic and volcanic rocks, which are intruded by intrusive (syenogranite, granodiorite), and sub-volcanic units (monzodiorite, quartz monzonite, and diorite porphyry). North of Bahariyeh intrusions are enriched in LREEs and LILs such K and Ba and decreases in HREEs and HFSEs such Nb and Ti that indicated magma formed in subduction zone. The negligible negative Eu anomaly (Eu/Eu*=0.66-0.89) reveal plagioclase is present at source and Nb deplation indicates slight contamination of magma with continental crust. The magma origin of this intrusion, is the low-grade partial melting of metasomatized mantle spinel lherzolite which has formed at 65 km depth. Mineralization occurred as vein-veinlet with NW-SE and NE-SW trend in direction faults. Propylitic, silicification, sericitic and argillic alterations have an extent in the region, and propylitic and silicification are present as a halo at margin of mineralized vein-veinlets. Hypogene ore-minerals include pyrite, chalcopyrite, and specular hematite, and chalcocite, malachite, azurite, goethite, and iron oxides are supergene minerals. Two types of vein-veinlets can be distinguished in district: 1) quartz+chalcopyrite+specular hematite and 2) specular hematite-rich. Significant amount are present of Cu (up to 2 %), Pb (up to 0.61%), and Zn (up to 0.2%) in quartz+chalcopyrite+specular hematite vein-veinlets. North of Bahariyeh area is probably similar to IOCG deposits based on evidence such structural control of mineralization, alterations type, mineralogical composition of ore-body, shape of mineralization, and geochemical anomalies.
