Granite Minerals Research Articles

Thermal stress-induced microcracking in building granite

Microcracking induced by wide fluctuations in temperature affects granite quality and durability, making the stone more vulnerable to decay. Determining the extent of that effect is not always straightforward, however, given the excellent durability of these materials.Four types of construction granite quarried in the region of Madrid, Spain, and frequently used in both the built heritage and in de novo construction (Alpedrete, Cadalso de los Vidrios, Colmenar Viejo and Zarzalejo) were exposed to 42 thermal cycles (105–20°C; UNE-EN, 14066, 2003). Petrographic and petrophysical properties were analysed using both destructive and non-destructive techniques. Microcracking generated in the granite stones by 42 thermal cycles had barely any impact on their petrophysical properties, which are the parameters normally assessed to establish material quality and durability. Their petrographic properties, which are not generally assessed in this type of studies, were affected, however. This study contends that petrographic analysis is needed to objectively quantify the actual quality and durability of the most highly resistant materials when petrophysical studies are inconclusive. Petrographic and fluorescence microscopy, along with fractography, are among the most prominent techniques for petrographic exploration. Thanks to the deployment of these techniques, mineral microcracking could be monitored throughout the present tests conducted.The microscopic findings revealed substantial micro-textural and microstructural change in and around the granite minerals, which play a prominent role in decay. The findings showed that pre-existing microcracks coalesced and generated further microcracking as decay progressed. Microcracking was most intense in Zarzalejo granite due to its textural characteristics determined by its high feldspar content. Microscopic observation revealed that the microstructure of feldspar minerals, with their crystallographic anisotropies and secondary mineral phases, favoured microcrack development. Zarzalejo granite exhibited lower quality and durability than Colmenar Viejo and Cadalso de los Vidrios granites, which were more resistant to heat treatment.

Fractionation of rare-earth elements during magmatic differentiation and weathering of calc-alkaline granites in southern Myanmar

AbstractGeochemical characteristics and rare-earth element (REE)-bearing minerals of calc-alkaline granites in southern Myanmar were investigated to identify the minerals controlling fractionation between light and heavyREE(LREE and HREE) during magmatic differentiation and weathering. The granites were classified on the basis of the mineral assemblages into two contrasting groups: allanite-(Ce)- and/or titanite-bearing granites; and more HREE-enriched granites characterized by hydrothermal minerals including synchysite(Y), parisite-(Ce), bastnäsite-(Ce), xenotime-(Y), monazite-(Ce), Y-Ca silicate, waimirite-(Y) and fluorite. This suggests that allanite-(Ce) and titanite are not stable in differentiated magma and HREE are eventually preferentially incorporated into the hydrothermal minerals. The occurrence of theREE-bearing minerals is constrained by the degree of magmatic differentiation and the boundary of two contrasting granite groups is indicated by SiO2contents of ∼74 wt.% or Rb/Sr ratios of ∼3–8. Fractionation between LREE and HREE during weathering of the granites is influenced by weathering resistance of theREE-bearing minerals, i.e. allanite-(Ce), titanite, theREEfluorocarbonates and waimirite-(Y) are probably more susceptible to weathering, whereas zircon, monazite-(Ce) and xenotime-(Y) are resistant to weathering. Ion-exchangeableREEin weathered granites tend to be depleted in HREE relative to the whole-rock compositions, suggesting that HREE are more strongly adsorbed on weathering products or that HREE remain in residual minerals.

Chemical and O-isotope compositions of amphiboles and clinopyroxenes from A-type granites of the Papanduva Pluton, South Brazil: Insights into late- to post-magmatic evolution of peralkaline systems

Clinopyroxene and amphibole are the main mafic minerals in peralkaline granites of the Papanduva Pluton, Morro Redondo Complex, one of the most important granitic occurrences within the Graciosa A-type Province, S-SE Brazil. Clinopyroxene is present as three distinct late- to post-magmatic textural generations of aegirine, as well as post-magmatic aegirine–augite. Amphibole is predominantly magmatic ferrorichterite and arfvedsonite, and post-magmatic riebeckite. Major and trace element compositions reveal evolutionary trends characterized by increasing Fe3+ and Na and decreasing Fe2+, Ca, HFSE, and REE contents from core to crystal rims; trace element and REE partitioning is controlled by the composition of the coexisting melts or fluid phases, as well as by crystal chemistry. δ18O values for minerals investigated range from +2.3 to +6.4‰ and correlate both with increasing degrees of alkalinity and quasi-solidus (sub-magmatic) deformation affecting several granites of the Papanduva Pluton. These deformation events played a significant role in the concentration and circulation of residual melts and fluid phases from which amphiboles and clinopyroxenes precipitated. Combined textural, chemical, and O isotope findings suggest that these fluids evolved through more oxidizing (close to the FMQ buffer), alkali- (i.e. peralkaline), fluorine-, and 18O-rich conditions, associated with higher abundances of HFSEs and REEs within a temperature interval between 750 and 700°C (late-magmatic stages) and 400–450°C (post-magmatic stages).

Compositional variations in tourmalines from peraluminous rocks of the Dipilto Granitic Batholith, Eastern Chortis Terrane, Nicaragua: tracers of magmatic to hydrothermal evolution

The granitoids of the Dipilto Batholith in northern Nicaragua range in composition from amphibole–biotite tonalite to cordierite–biotite and biotite granite. The petrographic and geochemical features indicate hybrid origin for the metaluminous granodiorite and tonalite (El Paraiso Suite). Dominant peraluminous granites (leucogranite dykes, Yumpali and La Piedra suites) represent a typical product of fractional crystallization of crust-derived melts. Tourmaline occurs as rare mineral in peraluminous granites of the Yumpali Suite (randomly distributed grains and quartz– tourmaline nodules), but is common in the younger leucogranite, pegmatite dykes and hydrothermal veins. Chemical variations (mainly X Fe and F) in tourmaline as well as in biotite are consistent with magmatic differentiation processes in granites and pegmatites. The presence of quartz–tourmaline hydrothermal veins indicates involvement of B-rich post-magmatic hydrothermal fluids at the final stage of the Dipilto Batholith evolution. Tourmaline chemistry evolved from Mg-rich schorl in peraluminous granites, to F-rich schorl–foitite in the hydrothermal veins. This evolutionary trend is typical of F-poor granite–pegmatite systems.

Zircon geochronology, geochemistry and stable isotopes of the Wang’ershan gold deposit, Jiaodong Peninsula, China

The Early Cretaceous gold deposits of the Jiaodong Peninsula, eastern China, define China’s largest gold province with an overall endowment estimated more than 3000tAu. The Wang’ershan gold deposit at the northern margin of the Jiaolai Basin in Jiaodong Peninsula of eastern China is located in the central-southern segment of the Wang’ershan fault zone. The major Mesozoic intrusions exposed in this region are the Linglong granite and the Guojialing granodiorite to the northeast of the deposit. Both these intrusions show high-K and alkaline signature. The Linglong granite displays peraluminous feature whereas the Guojialing granodiorite is metaluminous. Zircon U–Pb dating of the Linglong granite yields 206Pb/238U weighted mean age of 149.0±1.3Ma. The muscovite from the alteration zones associated with mineralization in the Linglong granite yields a plateau age of 130.35±0.96Ma, representing the initial phase of the hydrothermal activity. The δ34S values of pyrite from the gold mineralized veins range from 6‰ to 8.3‰ with the mean value of 7.66‰. The 3He/4He ratios of pyrite are in the range 1.58–2.71 Ra with a mean value at 2.168 Ra. The 40Ar/36Ar ratios show variation from 1220.3 to 1625.7 with an average of 1483.8. The δ18O values of the mineralizing fluids show a range of −2.13‰ to 7.5‰, with an average of 2.4‰. The δ18Dw values are in the range of −97.5‰ to −61.4‰, with a mean at −82.6‰. Detailed elemental and isotopic data suggest that the hydrothermal fluids in early stage were mainly magmatic and derived from the Guojialing granodiorite, and the ore-forming fluids in the main ore-forming stages evolved into a mixture of magmatic and meteoric water. The ore-forming materials were primarily derived from crust, with minor input of mantle components. The ore-forming fluids might be related to the subduction of the paleo-Pacific slab beneath the North China Craton and the associated asthenosphere upwelling and consequent lithospheric thinning.

Indicator Elements Combination’s Characteristic and Genesis of Four Types of Uranium Mineralization in China

China uranium mineralization in accordance with different metallogenic host rocks are mainly divided into four types: granite type uranium mineralization, volcano rock type uranium mineralization, the carbonate-siliceous-politic rock type and sandstone type uranium mineralizations, four types of uranium mineralization is due to different genesis and metallogenic environment, the indicator elements also have bigger difference. In this paper, through the national uranium resources potential evaluation project research results, describes characteristics of indicator elements of four types uranium mineralization, and from the perspective of element geochemistry, analyzes causes of the indicator elements combination.

Uranium migration and retention during weathering of a granitic waste rock pile

This study investigates the post-mining evolution of S-type granitic waste rocks around a former uranium mine, Vieilles Sagnes (Haute Vienne, NW Massif Central, France). This mine was operated between 1957 and 1965 in the La Crouzille former world-class uranium mining district and is representative of intra-granitic vein-type deposits. 50years after mine closure and the construction and subsequent re-vegetation of the granitic waste rock pile, we evaluate the environmental evolution of the rock pile, including rock alteration, neo-formation of U-bearing phases during weathering, and U migration. Vertical trenches have been excavated through the rock pile down to an underlying paleo-soil, allowing the investigation of the vertical differentiation of the rock pile and its influence on water pathways, weathering processes and U migration and retention. Arenization dominantly drives liberation of U, by dissolution of uraninite inclusions in the most alterable granitic minerals (i.e. K-feldspar and biotite). Retention of U in the matrix at the base of the waste rock pile, and in the underlying paleo-soil most likely occurs by precipitation of (nano-) uranyl phosphates or a combination of co-precipitation and adsorption reactions of U onto Fe (oxy)hydroxides and/or clay minerals. Even though U-migration was observed, U is retained in stable secondary mineral phases, provided the current conditions will not be modified.

Study on sorption and diffusion of Sr in crushed and intact basalt and granite investigated in through-diffusion experiments

This study investigates sorption and diffusion of strontium (Sr) in two potential host rocks (granite from Kingman Island and basalt from Penghu Island) by using batch and column methods. According to solid-phase analysis, the sorption component primarily contained iron–magnesium (Fe–Mg) minerals in basalt and granite. Moreover, the distribution coefficient (K d) of Sr in various concentrations obtained from batch tests indicated a higher sorption capacity in basalt than that in granite because of the 10 % Fe–Mg mineral content. According to the diffusive results in crushed and intact rocks, it showed that major retardation of Sr depended on the micro-porous structure of tested media, such as decreases of constrictivity and increases of tortuosity.

Residence sites and origin of noble gases in minerals as exemplified by ilmenite from the alkaline granites of the Kola Peninsula

Thermal analysis of helium release from ilmenite of alkaline granites (Ponoy Massif, Kola Peninsula) and extraction of gases by crushing, melting and vacuum stepwise heating of sample revealed that this mineral contains noble gases in several different residence sites (rs). Radiogenic 40Ar* and He are released within the temperature range of 400–600°C. However, in spite of the similar extraction temperatures, these gases occupy different rs: trapped excess 40Ar* is localized in relatively large inclusions (> 10 μm) and was almost completely released during crushing (more than 80%, first rs), whereas He is localized in “healed” α-tracks and was released during sample heating (second rs). The third rs is almost completely occupied by radiogenic He released at temperature around 1100°C; this temperature fraction has 4He/40Ar* = 830, whereas this ratio in whole sample is 10. Helium with the highest 3He/4He = 1.1 × 10−6, indicating a contribution of mantle helium, is released from the fourth rs. Observed distribution of helium and argon isotopes in ilmenite is consistent with geological data on the evolution of the Ponoy Massif. Quartz-feldspathic vein, from which ilmenite was collected, was formed by crystallization of residual alkali granitic melts; the melts contained mantle He, which finally was incorporated in primary inclusions (fourth rs). After formation, the massif rocks accumulated radiogenic 40Ar*, but lost more mobile radiogenic He. During Paleoproterozoic metamorphism of the Ponoy Massif, radiogenic 40Ar* was released from K-bearing minerals of granites and impregnated “potassium-poor” ilmenite (first rs). Then, trapped 40Ar* was preserved in mineral inclusions, while helium produced “in situ” during radioactive decay of U and Th mainly migrated from the mineral. At present, ilmenite is characterized by significant excess 40Ar*, and, simultaneously, by 4He deficit (second and third rs). Neither K-Ar, nor U-Th-He isotope systems of the mineral can be used for dating.

Strath development in small arid watersheds: Case study of South Mountain, Sonoran Desert, Arizona

Analyses of ephemeral granitic drainages of \<5 km^2^ at South Mountain metamorphic core complex, central Arizona, reveal a previously undocumented process of bedrock strath formation in this setting. Granitic channel banks experience a higher degree of mineral decay than that of granitic channel floors. Electron microscope observations show that grussification along the granitic channel banks occurs through abiotic processes of biotite oxidation and biotic processes associated with mycorrhizal fungi and roots of plants preferentially growing along channel banks. Digital image processing of backscattered electron microscope (BSE) images measured: (a) an enhancement of porosity along channel banks 2× to 5× greater than mid-channel positions; and (b) the gradual separation of grains over a 13-year period caused by the roots of Paloverde (*Parkinsonia microphylla*) trees. Ongoing mineral decay along banks facilitates differential erosion similar to Montgomery9s (2004) hypothesis. Ephemeral washes migrate laterally into the decayed granite of their banks and erode the distal end of bounding pediments, expanding beveled bedrock straths. Direct observations of strath widening in six drainages during three distinct flash floods reveal a range from 4 to 23 millimeters of lateral bank erosion and \<1 mm of channel bed abrasion. The widening of straths is likely limited by long-term rates of *in situ* physical separation of granitic minerals.

Tungsten accessory minerals in lithium-fluoric granites of the Russian Far East

By means of the technique of local analysis, the presence of a wide variety of tungsten and tungsten-containing accessories was first revealed in the composition of lithium-fluoric granites of the Far East, which represents a substantial similarity and regional peculiarity of these rocks. It was concluded that the tungsten accessory mineralization might be considered as an indication of the genetic relationship of the mineralization of the East Asian tin-tungsten zone to the Pacific rare-metal granites.

Genetically related Mo–Bi–Ag and U–F mineralization in A-type granite, Gabal Gattar, Eastern Desert, Egypt

Molybdenum–bismuth–silver and uranium–fluorine mineralization in the Gabal Gattar area are genetically related. Both are hosted in fractionated and hydrothermally altered A-type granite. While Mo–Bi–Ag ore is hosted in NS striking quartz veins, the U–F mineralization forms batches and micro-veinlets, controlled by NNE to NW trending structures. U was incorporated in late-magmatic hypogene minerals (e.g. zircon and xenotime) and in U–Th-minerals closely associated with fluorite. Molybdenite, native bismuth, galena, chalcopyrite, sphalerite, aikinite “PbCuBiS3”, berryite “S16(Cu,Ag)6 Bi7Pb3” and native silver were identified in the quartz veins. Fluid inclusions occur in fluorite (Type-1) associated with U minerals and in quartz (Type-2) from Mo-bearing veins. Type-1 and 2 inclusions homogenize at temperatures between 220°C and 106°C, their salinity ranges from 1.3 to 10wt.% NaCleq, respectively. F-rich fluids accumulated at the last stage of granite crystallization, extracted ore metals and deposited them in a shallow hydrothermal system. Mo, Bi and Ag precipitated earlier from saline fluids due to cooling, fluid mixing and wallrock sulfidation. U–F minerals precipitated from low-salinity fluids after high input of meteoric water.

New evidences for core processing of non-flint, lithic materials in the Late Palaeolithic and Mesolithic of Poland

In the Late Palaeolithic and Mesolithic core processing in Poland was dominated by flint raw materials. The present paper considers the occurrence of non-flint assemblages at the sites Lubrza and Ludowice (Polish Lowland). The focus is on recognition of petrographic studies, technology, typology and use-wear of inventories from both sites. The collections contain debitage, cores and different kinds of tools. As a result the identification of granite, sandstone, quartzite, gneisses, mudstones, slates and single minerals of quartzes and feldspars was established. The use-wear analysis brought good results only in case in porphyry artefacts. The described analyses are accompanied by a review of European non-flint assemblages from Late Palaeolithic and Mesolithic sites and discussion of the role of this type of raw material in core processing.

Role of hydrothermal activity in uranium mineralisation in Palnad Sub-basin, Cuddapah Basin, India

Unconformity related uranium mineralisation occurs in Banganapalle Formation of Palnad Sub-basin, Cuddapah Basin. Several evidences of hydrothermal activity exist in both basement granite and the cover sediments in Koppunuru and Rallavagu Tanda (R.V. Tanda) uranium prospects of Palnad Sub-basin. Profuse development of fracture filled veins consisting of epidote–quartz, chlorite–quartz and quartz is observed at various depths above and below unconformity. Fluid–rock interaction during the formation of these veins has resulted in the alteration of feldspars and mafic minerals of granite and arkosic quartzite into a mineral assemblage consisting of various proportion of illite, chlorite, muscovite and pyrite, with the intensity of alterations being highest near to the unconformity. Pyrite is often associated with illite dominant alteration zone. We infer that circulation of basinal brine through basement granite and cover sediments was responsible for mobilising uranium from granite and its precipitation at favourable locations in cover sediments. Increase in pH of ore fluid due to illitisation and chloritisation of wallrock together with availability of carbonaceous matter and pyrite as reductant have controlled the localisation of uranium mineralisation in Banganapalle Formation.

Mineralogical feature and geological significance of muscovites from the Longyuanba Indosinian and Yanshannian two-mica granites in the eastern Nanling Range

Emplacement P-T condition estimations using granites are important for understanding metamorphic and erosional processes of orogenic belt. Granites are widespread in South China and a majority of them are peraluminous. Particularly, over 91% of the Indosinian granites exposed in the region are peraluminous in composition. It is extremely hard to determine the pressure of intrusion of these peraluminous granites due to the absence of amphibole, a good mineral barometer commonly identified in metaluminous granites. Muscovite is a common mineral in peraluminous granites, certain kind of it could be used as a mineral barometer to constrain the emplacement pressure of peraluminous granites. In this paper, results of petrographic and geochemical studies of muscovites from the Indosinian and early Yanshanian two-mica granites at the Longyuanba in the eastern Nanling Range are reported. Based on petrographic studies, the primary muscovite can be discriminated from the secondary muscovites. Muscovites from the Indosinian two-mica granites are enriched in Ti, Al, Mg, and Na, and depleted in Fe and Mn. Geochemically, these muscovites were considered as primary, whereas those from the Yanshanian two-mica granites fall into the area of secondary muscovite on discrimination diagrams. Barometer estimations show that pressures calculated for primary muscovites are accurate, but those calculated for secondary muscovites are overestimated. The average pressure of emplacement of the Longyuanba Indosinian two-mica granites is 5.9 kbar, corresponding to ∼19 km in depth, suggesting that the Indosinian granitic magmas were probably generated by partial melting of a thickened crust root in a compressional tectonic setting.

A Monte Carlo-Based Approach for Groundwater Chemistry Inverse Modeling

Inverse geochemical modeling of groundwater entails identifying a set of geochemical reactions which can explain observed changes in water chemistry between two samples that are spatially related in some sense, such as two points along a flow pathway. A common inversion approach is to solve a set of simultaneous mass and electron balance equations involving water-rock and oxidation-reduction reactions that are consistent with the changes in concentrations of various aqueous components. However, this mass-balance approach does not test the thermodynamic favorability of the resulting model and provides limited insight into the model uncertainties. In this context, a Monte Carlo-based forward-inverse modeling method is proposed that generates probability distributions for model parameters which best match the observed data using the Metro-polis-Hastings search strategy. The forward model is based on the well-vetted PHREEQC geochemical model. The proposed modeling approach is applied to two test applications, one involving an inverse modeling example supplied with the PHREEQC code that entails groundwater interactions with a granitic rock mineral assemblage, and the other concerning the impact of fuel hydrocarbon bioattenuation on groundwater chemistry. In both examples, the forward-inverse approach is able to approximately reproduce observed water quality changes invoking mass transfer reactions that are all thermodynamically favorable.

A Tribute to Nicolai Pavlovich Yushkin, one of the discoverers of chernovite. Chernovite-(Y) and other arsenic minerals in rare-metal granites and greisens of the Far East

An assemblage of chernovite-(Y), As-bearing thorite, rooseveltite, and Cu and Fe arsenates has been revealed in Li-F granites, ongonites, and greisens of the Far East. The formation sequence of the above minerals is described in this paper. Chernovite-(Y) is a product of autometasomatic alteration of Li-F granite and ongonite, whereas other arsenates and As-thorite are products of greisenization.

Pogranichnoe Au-Bi occurrence, Eastern Sayan: Composition and link to magmatism

The Pogranichnoe ore occurrence of gold-bismuth type is closely related to Ordovician granitic rocks pertaining to the Sarkhoi granodiorite-granite complex of calc-alkaline series. This type of mineralization in the Eastern Sayan is described for the first time. The orebodies are represented by quartz veins and veinlets with greisenized granite as selvages. Three mineral assemblages consecutively follow one another: (1) pyrite-arsenopyrite, (2) base-metal with fahlore and Sb sulfosalts, and (3) gold-bismuth. The geological position of orebodies and character of microinclusions in accessory minerals of granites suggest that goldbismuth mineralization is related to granitoids.

Timing of hydrothermal activity associated with the Douzhashan uranium-bearing granite and its significance for uranium mineralization in northeastern Guangxi, China

The Miaoershan uranium (U) ore field in northeastern Guangxi is one of the important granite-related U deposits in south China and is closely related to the Douzhashan U-bearing granite. The Douzhashan granite contains primary U-rich accessory minerals, including monazite (UO2 = 0.98–1.75 wt%) and xenotime (UO2 = 1.48–6.14 wt%). Primary monazite and xenotime yield chemical ages of 231 ± 28 Ma and 230 ± 38 Ma by electron microprobe analysis and U-Pb isotopic ages of 220±6 Ma and 211±7 Ma by laser ablation-inductively coupled-mass spectrometry respectively. These ages demonstrate that the Douzhashan granite formed during the period of Indosinian magmatic activity. Back scattered electron imaging shows that monazite and xenotime are commonly altered to assemblages of low-U synchisite and apatite, which was associated with loss of U to hydrothermal fluids. U-Th-Pb analyses of secondary apatite yielded a chemical age of 136 ± 17 Ma, which corresponds to the timing of Cretaceous-Tertiary crustal extension in south China. We suggest that the heat and CO2 required for mineralization was the result of Yanshanian crustal extension, and that this triggered the breakdown of U-rich accessory minerals in the Douzhashan U-bearing granite. Uranium remobilization from the Douzhashan granite provided materials for mineralization within the granite and/or surrounding country rocks. Therefore, a combination of Indosinian compression and Yanshanian extensional overprint produced the hydrothermal U deposits associated with the Douzhashan granite.

Trace and REE element geochemistry of fluorite and its relation to uranium mineralizations, Gabal Gattar Area, Northern Eastern Desert, Egypt

Uranium mineralizations occur and form in a broad range of geologic setting and age, including magmatic to surfacial conditions, and there are numerous controls on their transportation and deposition, such as redox, pH, ligand concentration, complexation, and temperature. These temporal and spatial variations have caused a range of ore deposit mineral assemblages. Consequently, understanding their conditions of formation is still in its infancy. This research reports rare earth elements (REE) and trace elements of fluorite associated with hexavalent uranium mineralizations and tests of genetic models for the deposits. These data contribute to a better understanding of the variables controlling fluorite formation and uranium ore composition through understanding the evolution of these ore-forming hydrothermal systems. Fluorite in Gabal Gattar granite occurs as disseminations and/or thin veinlets and encrustations filling some uranium mineralized fissures and fractures along the northern margin of host granite mass. In the U-poor samples, fluorite forms well-developed large crystals that are commonly zoned. The zones are represented by alternating colorless and violet zones, and the outer zones are frequently dark violet. In the U-rich samples, fluorite is usually anhedral, unzoned, and has a dark violet color. The results of analysis of REE and trace element contents of fluorites using laser ablation inductively coupled plasma mass spectrometry indicate that total REE in the anhedral unzoned fluorite are elevated compared to the well developed zoned fluorite, and also total REE in dark violet zones of zoned fluorite are elevated with respect to the colorless zones. The fluorites and host granite are generally characterized by strongly negative Eu anomalies and slightly negative or chondritic Ce anomalies. Accordingly, REE patterns of the fluorite and host granite are roughly alike, indicating that the source of REE and trace elements of hydrothermal fluids is the host granite leached by fluids. Y/Y*, Ce/Ce,* and Eu/Eu* patterns show that fluorite clearly records the compositional evolution of the hydrothermal solutions that have transferred trace and REE from host granite during the fluid–wall rocks interactions. The high uranium contents of fluorite in Gabal Gattar granite suggest that parent fluids bearing fluorine have interacted with host granite to leach uranium from the accessory minerals of granite and tetravalent uranium minerals in reduced or weakly oxidized zones.