List of Articles Rare earth elements

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  1 - Investigation of geochemistry of minor and trace elements (rare earths) in the base metal vein mineralization Yaralujeh area (NW Ahar - East Azarbaijan)
  Zohreh Jabarzadeh Mehadi Moradi  Moayyed Zargar Faramarzi
  The Yaralujeh vein index is located about 40 km NW of Ahar, East Azarbaijan. Based on geochemical studies, the original host rock is microdioritic in composition with calc – alkaline character, situated in an active continental margin volcanic arc. The mineralization i More

  The Yaralujeh vein index is located about 40 km NW of Ahar, East Azarbaijan. Based on geochemical studies, the original host rock is microdioritic in composition with calc – alkaline character, situated in an active continental margin volcanic arc. The mineralization is occurred as disseminated, stockwork and veins - veinlets containing quartz, carbonate and sulfide minerals in altered subvolcanic rocks (microdiorite). Pyrite, sphalerite, galena and chalcopyrite are the most important sulfide minerals in this area. The most important alerations in this area are sericitic and carbonatization, and the main alteration minerals are quartz, sericite, illite, albite, kaolinite, leucoxene, pyrite and late carbonates. Bivariate diagrams of Ba + Sr vs. Ce + Y + La and Zr vs. TiO2 and also values less than one for TiO2 indicate a hypogenic origin for altered fluids. The spider diagrams of REEs, normalized to both chondrite and average upper continental crust, show differentiation of LREE from HREE and depletion of LREE relative to average upper continental crust. Based on geochemical indicators such as Hf / Sm, Nb / La and Th / La and LREE enriched relative to the HREE, the most important ion complexes transition metal are Cl- complexes. Ce, Eu and Pr (Eu/Eu*, Ce/Ce*, Pr/Pr*) anomalies in ore-bearing vein and host rock indicates near-neutral pH in a redox environment for the alteration fluids in Yaralujeh Index. Manuscript profile
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  2 - The Study of geochemical behavior of major and rare earth elements of garnet in the Darreh Vali pegmatites (North-east Boroujerd, Sanandaj-Sirjan zone)
  Somaye Rahmani Zahra Tahmasbi Xin Ding Ahmad Ahmadi Khalagi
  The pegmatites of Darreh Vali region is located in the north-east of Boroujerd which is a part of Sanandaj-Sirjan zone. In the Darreh Vali area, granodiorite bodies are cut by small pegmatitic dykes with NW–SE trend. The mineralogy of studied pegmatites consists of quar More

  The pegmatites of Darreh Vali region is located in the north-east of Boroujerd which is a part of Sanandaj-Sirjan zone. In the Darreh Vali area, granodiorite bodies are cut by small pegmatitic dykes with NW–SE trend. The mineralogy of studied pegmatites consists of quartz, alkali-feldspar (orthoclase and microcline), plagioclase, muscovite, garnet (almandine-spessartin), andalusite, tourmaline, and apatite. Chondrite-normalized patterns of the Darreh Vali pegmatite are characterized by low enrichments of LREE relative to HREE (LaN/YbN=1.76-4.04), with a relatively flat HREE distribution, and a strong negative Eu anomaly (Eu/Eu* =0.20-0.54). Major element chemistry of garnets in these pegmatites indicates a compositional zoning with decreasing MnO and increasing FeO from core towards the rim. In the case of the Darreh Vali pegmatites, all garnet crystals contain low CaO (0.15 to 0.29 wt.%) and high MnO (10.27 to 13.18 wt.%), which are similar to magmatic garnets from pegmatitic melts. On the MnO+CaO versus FeO+MgO (in wt. %) diagram, the composition of garnets shows that they probably crystallised in contact zones of pegmatite vein and from less evolved melts. LA-ICP-MS analyses show that analysed garnets have a high HREE, low LREE contents, and strong negative Eu anomaly (Eu/Eu*=0-0.41) in the core along with positive Eu anomaly (Eu/Eu*=0-3.22) at the rim. Y, HREE, Ti, Zr, Nb, Ta, Hf, U and Mn decrease from core to rim. These core-to-rim elemental variations are attributed to increasing fluid-phase and H2O activity in magma, along with increasing magma fractionation. REE patterns and Eu anomalies in zoned garnets suggest that they probably formed in reducing to oxidizing conditions. Manuscript profile
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  3 - The study of geochemical behavior of major and rare earth elements of garnet in the metamorphic rocks at Boroujerd area (Sanandaj-Sirjan Zone)
  فرشته  سجادی Somaye Rahmani NASIM Shamsaddini Zahra Tahmasbi   Hashemi Xink Ding Ahmad Ahmadi Khalagi
  Garnet–mica schist and hornfels rock units are exposed in the east and southeast of Boroujerd. These rocks consist primarily of quartz, K-feldspar, plagioclase, garnet (almandine–spessartine), chlorite, cordierite, andalusite, sillimanite, biotite, muscovite, and minor More

  Garnet–mica schist and hornfels rock units are exposed in the east and southeast of Boroujerd. These rocks consist primarily of quartz, K-feldspar, plagioclase, garnet (almandine–spessartine), chlorite, cordierite, andalusite, sillimanite, biotite, muscovite, and minor amounts of apatite, iron oxides (ilmenite and magnetite), and zircon. Whole-rock geochemical analyses reveal that the dominant protoliths are pelitic rocks. Major and trace element compositions suggest that the Boroujerd pelites were deposited along an active continental margin. Garnet porphryblasts in some hornfels samples are compositionally homogeneous with respect to major, trace and rare earth elements; this is attributed to the diffusional re-equilibration at high temperatures (>600 ºC). Garnet in schists and some hornfels samples show reverse compositional zoning with increasing Mn and decreasing Fe and Mg from core to rim. Higher concentrations of Mn in garnet rims are attributed to resorption during retrogression. The presence of chlorite around garnet porphryblasts in these schists also supports resorption during retrogression. In schists, concentrations of HREE and Y in garnet decrease from core to rim. These zoning patterns are interpreted to record garnet growth in a closed system (i.e., Rayleigh fractionation of compatible elements). Core–rim variations in the concentrations of trace elements and rare earth elements in garnet in the hornfels samples is negligible. The lack of prominent zoning of these elements in garnet from hornfels is interpreted as minimal fractionation due to rapid garnet growth. Manuscript profile
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  4 - Mineralogy, geochemistry, fluid inclusion and genesis of magnetite-apatite mineralization in the southwest of Hormuz Island, Iran
  Masoud Alipour-Asll عاطفه  فخری دودوئی
  20.1001.1.17357128.1399.14.56.7.0
  The study area is located about 8 km south of Bandar Abbas in Hormozgan Province. This area is in the south of the Zagros folded zone and part of the Hormuz series. The late Precambrian-early Cambrian rocks comprise intercalations of rhyolite-rhyodacite lava and tuff, c More

  The study area is located about 8 km south of Bandar Abbas in Hormozgan Province. This area is in the south of the Zagros folded zone and part of the Hormuz series. The late Precambrian-early Cambrian rocks comprise intercalations of rhyolite-rhyodacite lava and tuff, crystal ¬tuff, tuffaceous ¬shale, sandstone and evaporite layers. Iron mineralization along with apatite are found as dike, massive, vein-veinlets and disseminated forms in tuffaceous shale and crystalline tuff rock units. Based on iron oxides and apatite contents, mineralization can be divided into iron-oxides (mainly magnetite), iron oxides- apatite and apatite types. The main ore-forming minerals include magnetite, oligist, hematite, goethite and limonite, apatite, and gangue minerals are calcite, quartz and clay minerals. The Hormuz Island ores have a high concentration of rare earth elements (REE) and the total amount of REE in apatite-rich ores is up to 3%. The geochemical studies show that a strong positive correlation between P and REE. Comparison of the chondrite-normalized REE pattern of the Hormuz magnetite-apatite ores with those from the Bafq-Posht-e-Badam block and the Kiruna type iron ore deposits represent genetic similarity of mineralization. The homogenization temperature in the two-phased liquid and vapor (L+V) fluids in apatite minerals vary from 309 to 565°C (average 388°C), and salinity varies between 14.16 to 33.87 (20/80) wt.% NaCl. Finally, based on the field geology, mineralogy, geochemistry and fluid inclusion features, the Hormuz magnetite-apatite mineralization is classified in the Kiruna-type magnetite-apatite deposits group with magmatic-hydrothermal origin. Manuscript profile
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  5 - Geochemistry of rare earth elements and radioactive elements in phosphorites of Jeirud deposit, central Alborz, North of Iran
  milad najafi Mohammad yazdi khalegh khoshnoodi mehrdad behzadi
  Jeirud Phosphorite Mine is located in the phosphate-rich horizon of the Jeirud Formation of the Lower Devonian sediments in central parts of Alborz geotectonic zone, North of Iran. The sediments of this formation are mostly composed of detrital rocks such as sandstone, More

  Jeirud Phosphorite Mine is located in the phosphate-rich horizon of the Jeirud Formation of the Lower Devonian sediments in central parts of Alborz geotectonic zone, North of Iran. The sediments of this formation are mostly composed of detrital rocks such as sandstone, sandy shales and sandy limestones. Phosphorite mineralization is mainly concentrated in the shales of middle parts of the Jeirud Formation. In this research, we have studied the concentration and the possibility of exploitation of rare earth and radioactive elements in these phosphorites. Lithogeochemical samples were randomly collected from phosphorite horizons. The samples were analysed by ICP-MS and ICP-OES not only for REE but also for major oxides and radioactive elements. The geochemical data show that the average of P2O5 is 29.60 %. The average of U and Th is 4.97 and 8.64 ppm respectively. Also, this data show that concentration of REEs in these samples are , 3times more than rare earth elements in North American shales (NASC) and 2.6 times more than Past Archaen shales (PAAS). REE concentration of these phosphorites were normalised to North American shales (NASC) and Past Archaen shales (PAAS). The spider diagram shows positive patterns to REE, especially in Ce and Eu. Also, this spider diagram represents the diffrentiation of LREE with respect to HREE. This diffrentiation occurred due to preferential absorption mechanism and during late diagenesis in these sediments. The average concentration of P and REE is realtively high and it seems to be economic for next minning activites. But the average concentration of U and Th is too low and not economic for exploration. Manuscript profile