M. Badfar; M. R. Jannessary; R. Hosseinzadeh; M. Ghaderi
Abstract
This study is an investigation on geochemical exploration and economic geology of Qare-Naz 1:50,000 sheet, western Zanjan province. The scope of the study is to presentation of mineral pomissing area in a regional scale. For this reason, geochemical sampling was initially performed. The samples were ...
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This study is an investigation on geochemical exploration and economic geology of Qare-Naz 1:50,000 sheet, western Zanjan province. The scope of the study is to presentation of mineral pomissing area in a regional scale. For this reason, geochemical sampling was initially performed. The samples were analyzed by emission spectrometry, polarography and ICP methods. Then the results were processed using statistical methods. Anomaly samples were separated by method. In the control phase, the geochemical anomalies were studied using heavy mineral and economic geology studies viewpoint (field observation, study of polish and thin sections prepared from the mineralized zone as well as the analytical results for samples obtained from these zones). Combination of these results with geochemical anomalies the mineral promissing areas were defined, As follows: A) North – Northeast area has elements anomalies Au, Pb, Zn, Cu. B) Northwest area has elements anomalies Cu, Au, Fe, Mo, Bi and W. C) South – Southwest area has elements anomalies Cu, Pb, Zn, Mo, Mn and S.
Z. Mohammadzadeh; M. Ghaderi; S. Alirezaei; J. Hassanzadeh
Abstract
The Raziabad porphyry copper deposit is located 30 km north of the city of Jiroft, in southeastern part of the Urumieh-Dokhtar magmatic arc, southeastern Iran. Several intrusive bodies including diorite, gabbro, granodiorite and quartz-diorite associated with groups of dikes with similar composition ...
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The Raziabad porphyry copper deposit is located 30 km north of the city of Jiroft, in southeastern part of the Urumieh-Dokhtar magmatic arc, southeastern Iran. Several intrusive bodies including diorite, gabbro, granodiorite and quartz-diorite associated with groups of dikes with similar composition as well as dissimilar composition with the intrusions, intruded into the Raziabad porphyry system. The porphyry copper mineralization is associated with the granodiorite which intruded into dioritic, gabbroic and volcano-pyroclastic rocks. The magmatic activities continued after mineralization and lead to the emplacement of the quartz-diorite as well as intrusion of two groups of micro-granitic and andesi-basaltic dikes cutting the ore body, causing geometric complexity of the ore body. The alteration zones include potassic and magnetite-rich silicification zones, relatively restricted calcic zone, and propylitic zone. Phyllic alteration with restricted expansion and weak intensity overprinted on potassic alteration. The hypogene mineralization has occurred as disseminated, stockwork and veinlet styles closely associated with the potassic alteration zone. The main ore minerals are chalcopyrite+ magnetite+ pyrite with minor molybdenite, pyrrhotite, galena and sphalerite. The oxidation and enriched supergene zones are variable and restricted to the shallow levels. Hydrothermal activity in Raziabad deposit is classified into four stages on the basis of hydrothermal mineral assemblage and veinlet relation. The stages include: 1) calcium silicate-magnetite-quartz stage; 2) potassium silicate-sulfide-quartz-magnetite; 3) sericite-quartz-pyrite stage; 4) chlorite-epidote-calcite-pyrite±actinolite.
S Afzali; N Nezafati; M Ghaderi; J Ghalamghash; M.R Ghassemi; A Karimi Bavandpur
Abstract
The Gazestan magnetite–apatite deposit is situated 78 km east of Bafq. The Gazestan deposit is located in Bafq-Poshtebadam subzone of Central Iran structural zone. The rock units in the area belong to the Rizu series and consist of carbonate rocks, shale, tuff, sandstone and volcanics. In addition ...
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The Gazestan magnetite–apatite deposit is situated 78 km east of Bafq. The Gazestan deposit is located in Bafq-Poshtebadam subzone of Central Iran structural zone. The rock units in the area belong to the Rizu series and consist of carbonate rocks, shale, tuff, sandstone and volcanics. In addition to sedimentary and volcanic rocks, intrusive rocks in the form of stock and dyke outcrop as diorite gabbro, gabbro, diabase, quartz-monzonite and granite in various places. The green rocks with acidic to intermediate composition (trachyte and dacite demonstrate green color due to alteration) host iron and phosphate mineralization which in some localities, show subvolcanic facies. The alteration is more obvious in the volcanic rocks and includes chloritization, argillic, silicification, and also formation of mafic minerals such as epidote, tremolite and actinolite. The host rocks are strongly altered. Mineralization at the Gazestan deposit comprises a combination of iron oxides and apatite with various ratios accompanied by quartz and calcite, observed in different forms mainly within the trachytic-dacitic rocks and a small proportion in the rhyolites. Five forms of mineralization are distinguished in the area including massive iron ore with minor apatite, apatite-magnetite ore, irregular vein-veinlets (stockwork) in the brecciated green rocks, disseminated, and pure massive apatite veins. The host rocks in the Gazestan area plot on calc-alkaline field. Comparison of the most important characteristics of the Gazestan deposit (including tectonic setting, host rock, mineralogy, alteration, structure and texture) with those of various types of mineralization in the world suggest that the deposit is quite similar to the iron oxide - apatite deposits.
Gh Nabatian; M Ghaderi
Abstract
Iron oxide - apatite deposits are one of the most important REE resources that occurred in the Posht-e-Badam and Zanjan regions of Iran. REE mineralization in the Zanjan region is associated with Sorkhe Dizaj, Aliabad, Morvarid, Zaker, Oskand and Golestanabad iron oxide-apatite mineralization. The deposits ...
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Iron oxide - apatite deposits are one of the most important REE resources that occurred in the Posht-e-Badam and Zanjan regions of Iran. REE mineralization in the Zanjan region is associated with Sorkhe Dizaj, Aliabad, Morvarid, Zaker, Oskand and Golestanabad iron oxide-apatite mineralization. The deposits are located in the Tarom area, which is a part of western Alborz - Azarbaijan zone. The Eocene volcanic sequences such as olivine basalt, trachyandesite, andesite as well as volcanoclastic rocks are the main units in the area which are intruded by the late Eocene plutonic rocks. Plutonic rocks in the region include porphyric micro-quartzdiorite and quartz-monzonite to quartz-monzodiorite. Magnetite-apatite mineralization in the Zanjan region is related to quartz-monzonitic to quartz-monzodioritic rocks. The mineralization is observed in the form of vein and stockwork (irregular veins and veinlets of magnetite-apatite). In the Tarom magnetite-apatite deposits, apatite crystals are associated with magnetite some of which have sizes up to 20 cm. Monazite is the main REE-bearing mineral at these deposits occurring as inclusion in the apatite. The apatite minerals contain 0.4-1.6 wt% REE, and have an REE distribution pattern with a strange LREE/HREE enrichment. The results of this research indicate that the iron oxide - apatite mineralization in the Zanjan region is formed by a quartz-monzonitic magma with calk-alkaline affinity, which occurred in a magmatic arc setting. This research shows that the magnetite - apatite mineralization in the Zanjan region is an important REE concentration in Iran.
