Rare earth elements (REE)—Minerals in the Silius fluorite vein system (Sardinia, Italy)

Mondillo, Nicola; Boni, Maria; Balassone, Giuseppina; Spoleto, S.; Stellato, F.; Marino, Antonio; Santoro, Licia; Spratt, John

doi:10.1016/j.oregeorev.2015.11.016

Cited by 31 publications

(20 citation statements)

References 36 publications

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“…The REE geochemistry can also be used to determine the nature and evolution of a hydrothermal fluid in fluorite deposits (Bau et al, ; Mondillo et al, ). Fluorite often shows significant variation in the REE composition in hydrothermal deposits (e.g., Schwinn & Markl, ), and the fluid composition is an important controlling factor for REE behavior (Morgunov & Bykova, ).…”

Section: Discussionmentioning

confidence: 99%

Nature and Genesis of the Xiaobeigou Fluorite Deposit, Inner Mongolia, Northeast China: Evidence from Fluid Inclusions and Stable Isotopes

et al. 2018

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The recently discovered Xiaobeigou fluorite deposit is situated in the southern part of the Southern Great Xing'an Range metallogenic belt. Fluorite-bearing veins are rather common over the whole area. So far, 11 mineralized veins have been delineated at the Xiaobeigou deposit. Orebodies of the deposit are mainly hosted in Permian and Jurassic volcano-sedimentary rocks. The orebodies in this mining district exhibit a well-developed vertical zonation: from top to bottom, the orebodies can be divided into upper, central, and lower zones. The central zone is the most important part for mining operations, and it shows lateral zonation of fluorite mineralization. Rare earth element (REE) contents of the investigated samples are relatively low (less than 30.2 ppm). Furthermore, the REE contents of the fluorite grains from early to late ore stages exhibit a decreasing trend. All the fluorite samples show no or slightly positive Eu anomalies. Three types of fluid inclusions (FIs) are distinguished in the quartz and fluorite samples, including pure-liquid single-phase (PL-type), liquid-rich two-phase (L-Type), and vapor-rich two-phase (V-type) FIs. The FIs hosted in early-stage quartz were homogenized at 159.5-260.7 C (mainly 160-240 C); their salinities range from 0.18 to 1.22 wt.% NaCl eqv. The FIs hosted in early-stage fluorite yield slightly lower homogenization temperatures of 144.4-266.8 C (peaking at 140-220 C), which correspond to salinities of 0.18-0.88 wt.% NaCl eqv. Homogenization temperatures and salinities for the late stage are 132.5-245.8 C (mainly 160-180 C) and 0.18-1.40 wt.% NaCl eqv., respectively. Laser Raman spectroscopy of FIs shows that both the vapor and liquid compositions of the inclusions are dominated by H 2 O. The H-O isotopic compositions at Xiaobeigou suggest that the ore-forming fluids are predominantly of meteoric water origin. The Xiaobeigou deposit can be classified as a typical low-temperature hydrothermal vein-type fluorite deposit. Combined with regional data, we infer that the fluorite mineralization occurred during the Late Mesozoic in an extensional setting.

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Section: Discussionmentioning

confidence: 99%

Nature and Genesis of the Xiaobeigou Fluorite Deposit, Inner Mongolia, Northeast China: Evidence from Fluid Inclusions and Stable Isotopes

et al. 2018

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“…Eu as an oxidation sensitive element among REE, and is strongly dependent on temperature of depositional conditions (Möller et al, 1998;Mondillo et al, 2015;Dill, 2016Dill, , 2017 Figure 6, Eu anomaly values of the samples increase from L-11 to L-15. Abedini and Calagari (2015) suggested that, both diagenetic processes and the presence of plagioclase in the limestone of the Ruteh Formation were two important factors for generation of the positive Eu anomaly.…”

Section: Lanthanide Tetrad Effect In Limestone: a Tool To Environmentmentioning

confidence: 99%

“…On the basis of field observation, silicification, brecciation, and intense shearing, this limestone has characteristically peculiar geological features. Geologic aspects, mineralogy, and petrographic features of the limestone and the enclosed bauxite ores in the Kanigorgeh district were studied in detail by Abedini and Calagari (2013c, and 2015. Calcite, quartz, plagioclase, kaolinite, and Fe-oxides (hematite) are the most abundant mineral phases in the limestone (Abedini and Calagari, 2015).…”

Section: Lanthanide Tetrad Effect In Limestone: a Tool To Environmentmentioning

confidence: 99%

Lanthanide tetrad effect in limestone: a tool to environment analysis of the Ruteh Formation, NW Iran.

Abedini¹

2018

Acta Geodynamica Et Geomaterialia

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Exhibition of lanthanide tetrad effect in PAAS-normalized REE patterns, and non-CHARAC (non-CHArge-RAdius Control) behavior of Y/Ho and Zr/Hf in limestone of the Ruteh Formation, Kanigorgeh district (NW Iran), were studied in order to understand the reasons of occurrence of lanthanides tetrad effects. The computed values show that the third and fourth tetrads can be used as a good and powerful geochemical tool for investigation of physicochemical conditions of the depositional environment of the limestones. Here, a new mathematical-based method using polar coordination system for tetrad effect values (T p ) was used to evaluate under studying limestone. The correlation between T p and some geochemical parameters revealed that the limestone was likely deposited under two different conditions. The obtained results indicated that paleo-redox conditions, adsorption and scavenging by kaolinite and metallic oxides, degree of detrital input, diagenesis intensity, and complexation by polycarbonate ligands are likely the main mechanisms for occurrence of tetrad effect phenomenon in REE distribution patterns in the limestone. This means that tetrad effect phenomenon in REE distribution patterns of limestone can be applied as a good geochemical indicator to evaluate the deposition conditions in limestones. ARTICLE INFO

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“…The Y/Ho versus La/Ho diagram has been widely used to shed light on the evolution of fluorite ore formation (Bau & Dulski, 1995;Deng, Gong, et al, 2014;Mondillo et al, 2016;Pei et al, 2017). In the diagram (Figure 10a (Figure 10b) is used to differentiate the fluorite genesis (Möller et al, 1976;Sánchez et al, 2010;Sasmaz et al, 2018;Subías & Fernández-Nieto, 1995) for the Madiu deposit (Bau & Dulski, 1995).…”

Section: Samarium-neodymium Isotopesmentioning

confidence: 99%

Formation timing and genesis of Madiu fluorite deposit in East Qinling, China: Constraints from fluid inclusion, geochemistry, and H–O–Sr–Nd isotopes

Pei

Zhang

et al. 2019

Geological Journal

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The Heyu fluorite ore district is newly discovered in the East Qinling metallogenic belt (EQMB), central China. In this district, the large Madiu fluorite deposit contains five Mesozoic granite‐hosted orebodies. The deposit may have formed at shallow depth and occurred as continuous veins controlled by a series of N‐S‐ or NE‐trending, steeply dipping faults. The fluorite mineralization can be divided into two stages (I and II). Fluid inclusions in stage I fluorite homogenized at 132.2°C to 342.5°C (peak at 170°C–210°C) with salinities of 0.18 to 4.43 wt% NaCl equiv, whilst those in stage II fluorite homogenized at 122.2°C to 305.7°C (peak at 130°C–170°C) and salinities of 0.18 to 3.71 wt% NaCl equiv. Raman spectroscopic analysis of the fluid inclusions reveals that they comprise predominantly H2O. The rare earth element (REE) characteristics indicate that the deposit is of hydrothermal origin. The δ18OH2O (−8.8‰ to −0.5‰) and δDH2O (−69.0‰ to −61.9‰) values show a subhorizontal trend, suggesting that the oxygen isotopic compositions were modified by fluid–rock interactions. Fluid inclusion and stable isotopic data suggest that the ore‐forming fluids belong to a meteoric water‐sourced, medium–low temperature, and low salinity NaCl–H2O system. Initial fluorite 87Sr/86Sr ratios (0.708879–0.709682) resemble those of the Heyu batholith. The water–rock reaction, which leached Ca from the host rock and increased the fluid pH, was likely causative to the ore precipitation. Geochemical and mineralization features suggest that the Madiu fluorite deposit is best classified as a fault‐controlled hydrothermal vein‐type fluorite deposit. The Sm–Nd isochron age of 118.9 ± 7.8 Ma and its regional age correlation suggest that the fluorite mineralization occurred under regional extension or lithospheric thinning setting and that the fluorite mineralization was an important component of the Early Cretaceous mineralization event in the EQMB.

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Rare earth elements (REE)—Minerals in the Silius fluorite vein system (Sardinia, Italy)

Abstract: Rare Earth Elements (REE)-minerals in the Silius

Cited by 31 publications

References 36 publications

Nature and Genesis of the Xiaobeigou Fluorite Deposit, Inner Mongolia, Northeast China: Evidence from Fluid Inclusions and Stable Isotopes

Nature and Genesis of the Xiaobeigou Fluorite Deposit, Inner Mongolia, Northeast China: Evidence from Fluid Inclusions and Stable Isotopes

Lanthanide tetrad effect in limestone: a tool to environment analysis of the Ruteh Formation, NW Iran.

Formation timing and genesis of Madiu fluorite deposit in East Qinling, China: Constraints from fluid inclusion, geochemistry, and H–O–Sr–Nd isotopes

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