جستجوی مقالات مرتبط با کلیدواژه "kiruna-type" در نشریات گروه "زمین شناسی"

The Arabshah Fe mineralization is the only known magnetite-apatite mineralization at the Takab–Takht-e-Soleyman–Angouran subzone in southeast of Takab. The oldest rock units in the mineralization area include sedimentary succession of the Qom Formation that was intruded by the Pliocene Ayoub Ansar volcanic dome. Magnetite- apatite mineralization at the Arabshah occurs as vein-veinlets with E-W stright within the Ayoub Ansar dacitic dome. Brecciated zones containing narrow magnetite vein- veinlets occur at footwall and hanging wall of the main vein. Hydrothermal alterations include sodic-calcic, silicification and argillic. Magnetite is the only ore mineral in this mineralization which is accompanied with apatite, clinopyroxene, albite and quartz as gangue minerals. Mineralization textures in the Arabshah deposit include vein-veinlet, brecciated, disseminated, and replacement. REEs concentration within apatite crystals are more than 1%, and demonstrate LREE enrichment with high LREE/HREE ratio and distinctive negative Eu anomalies which is indicative for Kiruna- type iron ores. The result of fluid inclusion studies indicates the presence of two-phase and poly-phase inclusions include LV, VL, LVH, LVS and LVHS fluid inclusions with homogenization between 230-550 °C. The salinity of halite bearing poly-phase fluid vary between 35-60 wt.% NaCl equiv. Fluid inclusion data indicates that Arabshah magnetite-apatite mineralization originated from magmatic fluids. Evidences like mineral assemblages, hydrothermal alteration, ore structure and textures, geochemical characteristics and fluid inclusion data, indicate that the Arabshah magnetite-apatite mineralization can be classified as Kiruna-type iron ores.

The Tekieh Bala iron index is located in the south east of Kordestan province in Sanandaj- Sirjan geotectonic zone. Exposed rocks at the study area are including granite, gabbro, diorite, quartzmonzonite, quartzmonzodiorite and actinolite schist to chlorite schist.Orebody is located in the fault-beratited zone. Magnetite, hematite, goethite, limonite and pyrite included iron minerals in this index. Epidotization, chloritization, sericitization, actinolitization and silicification are the main alteration around the orebody. Geochemical studies of major and trace elements from the magnetite ore and use of diagrams provided by the various researchers shows that this index placed in group of iron oxide deposits, IOA sub-type and IOCG-type. REE Studies have shown, patterns of these elements, and calculated differential parameters emphasize the similarity of this deposit and IOA-type. Ore forming fluids were formed in differentiation and crystalization of intermediate intrusions rocks as a iron-rich hydrothermal fluids, mixing with the meteoric waters has been led to change in the environmental conditions and deposition of orebody.

Khanlogh magnetite-apatite deposit is located in northwest of Neyshabour. This area is situated in Binaloud structural zone and east of Tertiary Quchan-Sabzevar magmatic arc. Geology of the area is dacitic volcanic rock intruded by Oligocene subvolcanic rocks with composition of quartz monzodiorite and granodiorite. Miocene sedimentary rocks trusted on them. The magmatism in the area shows characteristics of I-type granitoids and related to subduction zone. Mineralization occurred in the form of vein and veinlet that is hosted by subvolcanic rocks. Veinlet, brecciate, massive, open space filling, and needle-like structures and textures is observed. Magnetite (low Ti, V, and S) and hydroxyl apatite associated with calcite, epidote, quartz, pyroxene, and chlorite are the most important minerals at deposit accompanied by minor pyrite and chalcopyrite. Hematite and malachite are the main secondary minerals. The main alterations of this deposit are propylitic, carbonate, silicification, and argillic where propylitic and carbonate alteration zones are most abundant than other alterations. Tectonic setting, host rock, mineralogy, alteration, and structure and texture studies indicate the Khanlogh deposit has the most similarity with the Kiruna type deposits.