Geology and Geochemistry of Homeijan Magnetite-Apatite Deposit (SW Behabad, Yazd province)

Mir Ali, Asghar Mokhtari, Mohamad Ebrahimi
Homeijan magnetite-apatite deposit is located in the SW of Behabad within the Posht-e-Badam Block at the Central Iranian Zone. This area mainly composed of Infra-Cambrian rocks and the most important rock unite is Rizu Series (Narigan Series) which is the host rock of Homeijan magnetite-apatite mineralization. Some magnetite-apatite mineralization crops out as lenses and veins in the Homeijan area. Field investigations demonstrate 3 outcrops of Fe mineralization in this area. The biggest lens
more » ... s 300 m length with average 20 m thickness. Mineralogically, these ores mainly composed of magnetite. Phosphate mineralization present in the marginal parts of the magnetite lenses. Based on the phosphate content, magnetite-apatite mineralization in the Homeijan area classified to 4 ore type include: 1-magnetite ore without apatite or with negligible apatite, 2-magnetite-apatite ore, 3-phosphatic ore and 4-actinolite-apatite-magnetite ore. Analyzed samples indicate that REEs have considerable content and vary between 827-9992 ppm. One sample from the apatite-actinolite zone demonstrate about 25500 ppm REEs concentration. Geochemical investigations indicate that REEs concentrations have a good positive correlation with P 2 O 5 contents and negative correlation with Fe content. Chondrite normalized REE patterns for all kind of mineralization show a similar pattern with a strong LREE/HREE fractionation and negative Eu anomaly, similar to that of Kiruna-type iron ores. KEYWORD Geochemistry, Magnetite-apatite deposit, Homeijan, Behabad, Posht-e-Badam.