Magnetite mineralization properties of Narm iron minewith respect to petrology and geochemistryof its adjacent gabbroic- dioritic rocks (North of Tabas, South Khorasan Province)

The Narm iron mine located in the north of Tabas, the South Khorasan province in the north east of Iran. Magnetite is the main mineral, is associated with actinolite as the most abundant silicate mineral as well as apatite as the micro crystalline localized aggregations in the mineralization zone. The iron ore grade ranges from 50 to 55 wt% and 3% sulfur content. On the base of field observation, geochemical investigation, the rare earth elements pattern and their distribution there are many similarities between the mineralization of Narm mine and some magnetite-apatite iron oxide (IOA) deposits. Lithologically, the area mainly includes limestone-dolomite units of the Rizu formation in which gabbroic-dioritic magma is intruded. The dominant texture of these intrusive rocks is hypidiomorphic granular, dominated by plagioclase, amphibole (hornblende), pyroxene (mostly diopside), apatite as an important accessory mineral and opaque minerals mainly magnetite and pyrite. The rocks under study are alkaline in nature formed in within plate zone. These gabbroic-dioritic rocks were produced as a result of low degree partial melting of mantle wedge with garnet lherzolite composition. Any geochemical evidence indicating of crustal contamination is not observed. .