Alkali metasomatism as a process for Ti–REE–Y–U–Th mineralization in the Saghand Anomaly 5, Central Iran: Insights from geochemical, mineralogical, and stable isotope data

Deymar, Saleh; Yazdi, Mohammad; Rezvanianzadeh, Mohammad Reza; Behzadi, Mohammad Hassan

doi:10.1016/j.oregeorev.2018.01.008

Cited by 20 publications

(14 citation statements)

References 80 publications

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“…The third magnetite end-member component (Mgt C) therefore possibly records magnetite that formed from fluids that had exchanged O isotopes with the marine sedimentary carbonate rocks that are associated with the ironoxide deposits in central Iran, and/or with CO 2 that was derived from those carbonate rocks. The possible relevance of fluid interaction with carbonate rocks in the formation of the IOA deposits is also demonstrated by the presence of abundant secondary carbonate minerals in most of the deposits in central Iran (Jami et al, 2007;Daliran et al, 2010;Heidarian et al, 2017;Deymar et al, 2018).…”

Section: Mgt C: Influence Of Oxygen From Marine Sedimentary Carbonatesmentioning

confidence: 99%

Triple oxygen isotope variations in magnetite from iron-oxide deposits, central Iran, record magmatic fluid interaction with evaporite and carbonate host rocks

Peters

Alibabaie

Pack

et al. 2019

Geology

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Oxygen isotope ratios in magnetite can be used to study the origin of iron-oxide ore deposits. In previous studies, only 18O/16O ratios of magnetite were determined. Here, we report triple O isotope data (17O/16O and 18O/16O ratios) of magnetite from the iron-oxide–apatite (IOA) deposits of the Yazd and Sirjan areas in central Iran. In contrast to previous interpretations of magnetite from similar deposits, the triple O isotope data show that only a few of the magnetite samples potentially record isotopic equilibrium with magma or with pristine magmatic water (H2O). Instead, the data can be explained if magnetite had exchanged O isotopes with fluids that had a mass-independently fractionated O isotope composition (i.e., MIF-O), and with fluids that had exchanged O isotopes with marine sedimentary carbonate rocks. The MIF-O signature of the fluids was likely obtained by isotope exchange with evaporite rocks of early Cambrian age that are associated with the IOA deposits in central Iran. In order to explain the triple O isotope composition of the magnetite samples in conjunction with available iron isotope data for magnetite from the deposits, we propose that magnetite formed from magmatic fluids that had interacted with evaporite and carbonate rocks at high temperatures and at variable water/rock ratios; e.g., magmatic fluids that had been released into the country rocks of a magma reservoir. Additionally, the magnetite could have formed from magmatic fluids that had exchanged O isotopes with SO2 and CO2 that, in turn, had been derived by the magmatic assimilation and/or metamorphic breakdown of evaporite and carbonate rocks.

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Section: Mgt C: Influence Of Oxygen From Marine Sedimentary Carbonatesmentioning

confidence: 99%

Triple oxygen isotope variations in magnetite from iron-oxide deposits, central Iran, record magmatic fluid interaction with evaporite and carbonate host rocks

Peters

Alibabaie

Pack

et al. 2019

Geology

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“…The calculated stable isotopic compositions of Th-REE-forming fluids in equilibrium with calcite and actinolite reflect the composition of magmatic waters (Figures 7 and 8), like Se-Chahun IOA and Saghand Anomaly 5 deposits (Deymar et al, 2018;Mirzababaei et al, 2021) (Table 3).…”

Section: Discussionmentioning

confidence: 77%

“…Th-REE (at the Choghart mine) and REE-U-Th mineralization (Deymar, Yazdi, Rezvanianzadeh, & Behzadi, 2018) occurs in marginal alteration zones of the iron ore deposits.…”

mentioning

confidence: 99%

Formation and evolution of Th–REE mineralizing fluids at the Kiruna‐type Choghart iron oxide–apatite deposit, Central Iran: Insights from fluid inclusions and H‐C‐O isotopes

et al. 2022

Self Cite

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The Choghart iron oxide–apatite (IOA) deposit is one of the largest iron mines of the Bafq district in Central Iran. This deposit is hosted by the Early Cambrian rhyolites, and diabase dikes crosscut both host rocks and the ore bodies. The Choghart rhyolites erupted in a continental arc setting, while the Choghart diabase dikes formed in a back‐arc basin environment. Thorite, minor titanite, and REE‐oxide are the main hosts of Th and REEs. The mineralogy and geochemistry support that the Th–REE mineralization formed at relatively reduced conditions. The presence of calcite accompanied by thorite and titanite suggests that Th and REE probably migrated as carbonate complexes in the mineralizing hydrothermal fluids. Microthermometric data of calcite associated with thorite indicate that the salinity of the ore‐forming fluids varies from 20 to 30 wt% NaCl equivalent with temperature estimates between 300 and 370°C. The narrow range of homogenization temperature and low salinities of the fluid inclusions imply the presence of only one fluid phase in the Th–REE mineralization. The calcite δ13CPDB (−3.9 to −4.1‰) and δ18OSMOW (6.6–7.0‰) support a magmatic source for the ore‐forming fluids. Actinolite δD (5.55–6.72‰) and δ18O (−100.8 to −82.4‰) also suggest a magmatic source of the ore‐forming fluids. Microthermometric data imply that fluid–rock interaction and cooling were critical factors triggering the thorite precipitation at Choghart IOA deposit. Stable isotopic data indicate that post‐magmatic fluids derived from rhyolitic magmas played a significant role in the Th–REE mineralization.

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“…The Th/U ratios were <1 in the mineralized U samples (metasomatized). A few metasomatized samples had Th/U values higher than one [ 42 ]. The high ratios of Th/U (1.21) in mineralized rocks in the Abu Hadeida area could be related to the late magmatic mineralization of these granitic rocks, suggesting the ascent of late magmatic fluids through weak planes such as faults and the contact of these rocks with older granitoid.…”

Section: Discussionmentioning

confidence: 99%

Assessing the Radiological Risks Associated with High Natural Radioactivity of Microgranitic Rocks: A Case Study in a Northeastern Desert of Egypt

Abed

Monsif

Zakaly

et al. 2022

IJERPH

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This study aimed to evaluate the radiological hazards of uranium (238U), thorium (232Th), and potassium (40K) in microgranitic rocks from the southeastern part of Wadi Baroud, a northeastern desert of Egypt. The activity concentrations of the measured radionuclides were determined by using a gamma-ray spectrometer (NaI-Tl-activated detector). The mean (238U), (232Th), and (40K) concentrations in the studied rocks were found to be 3680.3, 3635.2, and 822.76 Bq/kg, respectively. The contents in these rocks were elevated, reaching up to 6.3 wt%. This indicated the alkaline nature of these rocks. The high ratios of Th/U in the mineralized rocks could be related to late magmatic mineralization, suggesting the ascent of late magmatic fluids through weak planes such as faults and the contact of these rocks with older granites. The present data were higher than those of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) guideline limits. All the radiological hazard results indicated high human health risks. This confirmed that this area is not radiologically safe, and care must be taken when working in this area. This study showed that the area under investigation had high U content suitable for uranium extraction that could be used in the nuclear fuel cycle.

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Alkali metasomatism as a process for Ti–REE–Y–U–Th mineralization in the Saghand Anomaly 5, Central Iran: Insights from geochemical, mineralogical, and stable isotope data

Cited by 20 publications

References 80 publications

Triple oxygen isotope variations in magnetite from iron-oxide deposits, central Iran, record magmatic fluid interaction with evaporite and carbonate host rocks

Triple oxygen isotope variations in magnetite from iron-oxide deposits, central Iran, record magmatic fluid interaction with evaporite and carbonate host rocks

Formation and evolution of Th–REE mineralizing fluids at the Kiruna‐type Choghart iron oxide–apatite deposit, Central Iran: Insights from fluid inclusions and H‐C‐O isotopes

Assessing the Radiological Risks Associated with High Natural Radioactivity of Microgranitic Rocks: A Case Study in a Northeastern Desert of Egypt

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