Related Minerals Research Articles

The timing of the Middle Triassic magmatism in the Dolomites area (Southern Alps, Italy): U[sbnd]Pb geochronology of zircon and titanite hosted in plutonic rocks and phonolite dykes

The Middle Triassic magmatic event in the Southern Alps (Italy) is characterised by the emplacement and eruption of multiple magma batches with different geochemical affinities in a short time span. In this work, we present the first geochemical and geochronological data on highly differentiated alkaline dykes (phonolites) exposed in and near the Middle Triassic Predazzo magmatic complex (Southern Alps, Italy) and a first complete geochronological survey of the Predazzo pluton. The phonolites, cutting the Middle Triassic volcanic sequences, are sodalite- and aegirine-bearing and have titanite, apatite and magnetite as accessory phases. Their trace element concentration reflects a geochemical signature similar to the orogenic-like signature typical of the Middle Triassic magmatic rocks of the Predazzo complex. New in situ UPb dating on titanite from the phonolite dykes and UPb dating on zircon separates from all the magmatic units of the Predazzo pluton show that the phonolite dykes were emplaced between 233.8 ± 3.1 Ma and 238.1 ± 4.5 Ma, i.e., overlapping to and postdating the emplacement and crystallisation of plutonic rocks, which yield ages ranging from 237.97 ± 0.15 Ma to 238.31 ± 0.13 Ma. The ages obtained for the diverse suites of the pluton are in good agreement with previous dating and show that silica-saturated to -undersaturated rocks were placed within the same context in a short time span. Thermometry and hygrometry on titanite, clinopyroxene and K-feldspar revealed that phonolites represent volatile- and REE-rich (H2O = 8 ± 0.6 wt%) highly differentiated alkaline melts intruding at relatively low T (752–868 °C), which easily caused the spatially related CuW mineralisation. Comparisons with sub-volcanic rocks exposed in the Central (Edolo) and Western Alps (Finero mafic complex) indicate that the phonolites still preserve the orogenic signature of the Middle Triassic event in the Southalpine, that characterise all magmas emplaced before the opening of the Alpine Tethys in the Late Triassic. These new geochronological constraints on the Predazzo pluton and phonolite dykes enable us to outline the complete sequence of magmatic events associated with the emplacement of the Predazzo volcano-plutonic complex during Mid-Triassic and to speculate about the genesis of CuW mineralisation.

The composition of magmatic-hydrothermal fluids and their related metal mineralization

The composition of magmatic-hydrothermal fluids and their related metal mineralization

Fluid inclusion and multiple isotope geochemical constraints on the hydrothermal evolution and metal sources of the Qiaomaishan Cu–W skarn deposit, eastern China

The Xuancheng ore district of eastern China is a newly discovered district within the Middle and Lower Yangtze River Metallogenic Belt (MLYB) that hosts several magmato-hydrothermal related mineral deposits. The Qiaomaishan deposit is a representative example of the skarn deposits within this district and is also the only deposit within the district that hosts tungsten mineralization. However, the source of metals and the hydrothermal evolution of the mineralizing system that formed this deposit remain controversial. This study addresses these issues using new fluid inclusion microthermometric and isotopic data, including fluid inclusion H, quartz O, sulfide S, and pyrite Pb data, which constrain the evolution of the hydrothermal fluids within the system and the source of metal within the Qiaomaishan deposit. This study identified three main stages of hydrothermal evolution and paragenesis within the deposit, namely pre-ore (stage 1), syn-ore (stages 2 and 3), and post-ore formation stages. Stage 1 garnet (andradite)-hosted fluid inclusions homogenize between 390 °C and 590 °C and have salinities of 9–20 wt% NaCl equivalent whereas stage 2 quartz-hosted fluid inclusions homogenize between 200 °C and 460 °C and have salinities of 5–18 wt% NaCl equivalent. Finally, stage 3 quartz- and calcite-hosted fluid inclusions homogenize at temperatures of 120 °C–240 °C and 3–15 wt% NaCl equivalent salinities. The stage 2 quartz has oxygen and hydrogen isotopic compositions (δDfluid from −99 ‰ to −57 ‰; δ18Ofluid from 4.0 ‰ to 6.1 ‰) that are close to those expected for magmatic fluids, whereas stage 3 quartz (δDfluid from −105 ‰ to −86 ‰; δ18Ofluid from −1.7 to −0.6 ‰) records the mixing of meteoric and hydrothermal magmatic fluids. These fluid inclusion data suggest that cooling was the main mineralizing process involved in stages 1 and 2, and this process may favor the enrichment of tungsten and copper in the residual hydrothermal fluids. In contrast, fluid mixing became increasingly important between stages 2 and 3, leading to a reduction in salinity and temperature as well as changes in fluid isotopic compositions. Water–rock (W/R) interaction is also likely to have been an important process during deposit formation. The δ34S (2.7 ‰–5.7 ‰ with a mean of 4.3 ‰) of sulfides from the Qiaomaishan deposit also provide evidence that the sulfur within the deposit has a magmatic origin. The homogeneous pyrite Pb isotopic data (206/204Pb = 18.158–18.518, 207/204Pb = 15.592–15.650, and 208/204Pb = 36.179–38.634) for samples from the Qiaomaishan deposit further indicates that the metals within the deposit were derived from both mantle and crustal sources. In summary, the Qiaomaishan deposit formed from hydrothermal fluids derived from a magmatic source that subsequently cooled, mixed with meteoric water, and underwent W/R interaction, causing sulfide precipitation. The large-scale folding present in this area may also have been a key focus for mineralizing fluids and this a potential vector for use in mineral exploration as these structures focused both magmatism and fluid flow, promoting the formation of the skarn mineralization in this region.

Apatite and Monazite Geochemistry Record Magmatic and Metasomatic Processes in Rare Earth Element Mineralization at Mountain Pass, California

Abstract The largest rare earth element (REE) deposit in the United States is a carbonatite intrusion at Mountain Pass in the Mojave Desert, California. Despite a clear spatiotemporal association of alkaline silicate and carbonatite intrusions at Mountain Pass, a genetic model of their mutual formation has not been resolved. The Mountain Pass carbonatite has long been upheld as an example of a primary magmatic body, but this has not been investigated in detail at the mineral scale. This study investigates the geochemistry of apatite and monazite grains from the alkaline silicate and carbonatite stocks and dikes of the Mountain Pass district to elucidate the magmatic history of the intrusive suite and identify the potential role of fluids in REE mineralization. Three apatite populations are identified in the alkaline silicate rocks. A primary magmatic apatite group supports intrusion of the stocks as separate pulses of magma derived from a spatially extensive metasomatized mantle source region. The second group implicates the role of a regional fluid that mobilized light REEs from apatite grains. Low Sr concentrations and negative Eu anomalies in cores of a minor group of inherited apatite support assimilation of crustal material in the formation of the intrusive suite. Analyses of monazite and apatite grains from the carbonatite orebody also reveal a mix of primary magmatic and metasomatic (fluid related) minerals. Compositional similarities between primary phosphates in the carbonatite and alkaline silicate rocks support a genetic link between the intrusions. The impact of fluids on mineralization in the carbonatite orebody indicates the Mountain Pass carbonatite should not be classified as a purely magmatic REE deposit.

Mitigating the Adverse Effects of Salt Stress on Pepper Plants Through Arbuscular Mycorrhizal Fungi (AMF) and Beneficial Bacterial (PGPR) Inoculation

This study investigates arbuscular mycorrhizal fungi (AMF), plant growth-promoting rhizobacteria (PGPR), and their combined application under salt stress (200 mM NaCl), emphasizing their synergistic potential to enhance plant resilience. Conducted in a controlled climate chamber, key parameters such as plant height, biomass, SPAD values, ion leakage, relative water content (RWC), osmotic potential, and mineral uptake were assessed. Salt stress significantly reduced plant growth, chlorophyll content, and nutrient absorption. However, AMF and PGPR improved plant performance, with co-inoculation showing the highest efficacy in increasing RWC, nutrient uptake, and maintaining membrane stability. AMF and PGPR treatments enhanced potassium retention and reduced sodium and chloride accumulation, mitigating ionic imbalances. The improved chlorophyll content and water relations under co-inoculation demonstrate the potential of these biostimulants to boost photosynthesis and plant resilience. These findings highlight AMF and PGPR as eco-friendly solutions for sustainable agriculture, promoting crop productivity and stress tolerance under saline conditions.

Vanadium extraction from vanadinite and high carbon v-bearing stone coal by coupling reduction smelting and oxalic acid hydrothermal leaching

Vanadinite and high-carbon vanadium-bearing (V-bearing) stone coals are important vanadium sources widely used in vanadium extraction. The traditional sulfuric acid leaching method for extracting vanadium consumes a large amount of acid, wastes significant amounts of lead and carbon, and causes serious environmental pollution. This study discusses the integration of reduction smelting and oxalic acid hydrothermal leaching for processing vanadinite and high-carbon V-bearing stone coals. Specifically, high-carbon V-bearing stone coal is selectively added to vanadinite to produce coarse lead blocks and V-bearing slag during reduction smelting. Then, the oxalic acid hydrothermal leaching process is employed to extract vanadium from the V-bearing slag. This approach reduces the waste of lead and carbon resources and achieves co-extraction of vanadium from both V-bearing minerals. The results show that when the mass ratio of high-carbon V-bearing stone coal to vanadinite is 25%, and smelting is conducted at 1150°C for 15 min under argon protection, a separation efficiency of 90.67% for metallic lead and V-bearing slag is achieved, the grade of V2O5 in vanadium slag is 12.37%, and the recovery rate is 95.64% by ICP-OES analysis. Furthermore, the leaching rate of vanadium in the V-bearing slag can reach 85.34% via oxalic acid hydrothermal leaching under conditions of a leaching temperature of 100°C, a leaching duration of 30 min, an oxalic acid concentration of 25 wt%, a liquid-to-solid ratio of 10:1 mL/g, and a stirring speed of 500 rpm. The integration of reduction smelting and oxalic acid hydrothermal leaching offers benefits such as improved resource utilization, waste reduction, cost savings, and environmental enhancements. Thus, the findings of this research can serve as references for the vanadium extraction processes of related vanadium-containing minerals.

Controls on Corundum Formation: Metasomatism of Ultramafic Rock, Nattavit, South-East Greenland

Abstract The geotectonic setting for plumasite-type corundum occurrences is understudied, even though it is of importance for the understanding of trace-element patterns used for fingerprinting of ruby and sapphire. Mineral reactions related to metasomatism caused by pegmatite intrusion into ultramafic rock result in a characteristic trace element signature in corundum and thereby control its colour. The Nattivit area, Isertoq Terrane, South-East Greenland, provides a natural laboratory to investigate these mineral reactions and corundum trace element patterns given the excellent exposure of a typical plumasite-type occurrence where pegmatites intruded ultramafic rocks of different composition, namely lherzolite and dunite. The pegmatite dykes are 10 to 50 cm wide in the ultramafic rocks, whereas the adjacent alteration zone in the ultramafic rock reaches widths between 10 and 30 cm. Metasomatism resulted in desilication of the pegmatites and a decrease in Ca, Mg, K, Mn, Al and Fe away from the centre of the pegmatite dyke. Chromium, Ni, Mg, Fe, Sc, Co, V, Zn, Ti and Mn in the metasomatic reaction zones are predominantly derived from the ultramafic rock. We identify three zones with different mineral assemblages. In the lherzolite, tschermakite and biotite are formed in the centre of the reaction zone, which is followed by anorthite-rich plagioclase, hercynite, dolomite and ultimately pink corundum that occurs in the most heavily reacted part of the metasomatic reaction zone. The metasomatic reaction zones in the ultramafic rock include an intense reactionzone at direct contact to the pegmatite dyke with biotite and actinolite, and two alteration zones further away from the pegmatite dyke with enstatite, actinolite, anthophyllite, phlogopite, dolomite, sulphide, apatite and chrome-spinel. In the dunite, no biotite formed and hence, corundum contains more Fe, Mg and Ti. The plumasite-type corundum from Nattivit contains more Fe than Cr, which is typical of pink corundum hosted in mafic-ultramafic rocks. The corundum-forming reaction is dated from the pegmatite vein to 1843±4 Ma (U-Pb zircon age), which is coinciding with convergence of the Rae and North Atlantic cratons resulting in the Nagssugtoqidian Orogen. Only syn-tectonic, corundum-normative, peraluminous, calc-alkaline pegmatites of granitic to granodioritic composition that intrude into ultramafic rocks in the upper plate formed corundum in this area. The pegmatites are classified as muscovite class granitic pegmatites and intruded at upper amphibolite facies conditions. These pegmatites possible originated from partial melting of mafic granulite or a subducted oceanic plate. The formation of granitic pegmatites and related corundum mineralization in the upper plate of a collisional orogen described here is comparable to other corundum occurrences, e.g. Polar Urals, and thus is regarded as a typical geotectonic setting for plumasite-type corundum.

Investigation of geochemically induced permeability alteration in geothermal reservoirs and its implications for sustainable geothermal energy production

Geothermal resources constitute a significant portion of the world's low-carbon, renewable energy potential, with about 75% classified as low-temperature. One such potential resource exists in Precambrian basement rocks underlying the Williston Basin in southern Saskatchewan, Canada, with a reservoir temperature of 120 °C. However, geochemically induced permeability alteration in these highly reactive low-temperature granitoid resources poses a significant risk to long-term heat production. To assess and potentially mitigate this risk, we conducted a geochemical and mineralogical study of both altered and unaltered samples. Our findings facilitated the parameterization of geochemical simulations of water-rock interactions to predict mineral volume changes and, by extension, draw inferences on porosity and permeability changes resulting from these interactions. The simulations indicate an increased mineral volume in both samples, yet geothermal alteration of the unaltered, and thus more reactive, rocks induced relative mineral volume changes about 30% greater than those in the altered rocks. The resulting absolute change in porosity is 0.5 vol% for the unaltered rocks and 0.35 vol% for the altered rocks. Utilizing an empirical porosity-permeability relationship, the computed change in permeability indicates that the unaltered basement rock experienced a greater change in total permeability than the altered basement rocks. Additional calculations demonstrate the sensitivity of the porosity-permeability equation to critical porosity and power exponent, forecasting various scenarios with permeability changes ranging from 1.0 × 10−13 to 1 × 10−20 m2. Consequently, we infer that altered, permeable zones of the examined Precambrian basement rocks are likely to offer favourable conditions for sustained, multi-decade heat production, and thus should be targeted over less altered zones to justify initial capital expenditures. Globally, geothermal heat extraction from these rocks remains an underexplored yet promising resource for generating reliable, low-carbon renewable energy, crucial in our efforts to decarbonize the global economy.

SLAMF8 regulates osteogenesis and adipogenesis of bone marrow mesenchymal stem cells via S100A6/Wnt/β-catenin signaling pathway

BackgroundThe inflammatory microenvironment plays an essential role in bone healing after fracture. The signaling lymphocytic activation molecule family (SLAMF) members deeply participate in inflammatory response and make a vast difference.MethodsWe identified SLAMF8 in GEO datasets (GSE129165 and GSE176086) and co-expression analyses were performed to define the relationships between SLAMF8 and osteogenesis relative genes (RUNX2 and COL1A1). In vitro, we established SLAMF8 knockdown and overexpression mouse bone marrow mesenchymal stem cells (mBMSCs) lines. qPCR, Western blot, ALP staining, ARS staining, Oil Red O staining and Immunofluorescence analyses were performed to investigate the effect of SLAMF8 in mBMSCs osteogenesis and adipogenesis. In vivo, mice femoral fracture model was performed to explore the function of SLAMF8.ResultsSLAMF8 knockdown significantly suppressed the expression of osteogenesis relative genes (RUNX2, SP7 and COL1A1), ALP activity and mineral deposition, but increased the expression of adipogenesis relative genes (PPARγ and C/EBPα). Additionally, SLAMF8 overexpression had the opposite effects. The role SLAMF8 played in mBMSCs osteogenic and adipogenic differentiation were through S100A6 and Wnt/β-Catenin signaling pathway. Moreover, SLAMF8 overexpression mBMSCs promoted the healing of femoral fracture.ConclusionsSLAMF8 promotes osteogenesis and inhibits adipogenesis of mBMSCs via S100A6 and Wnt/β-Catenin signaling pathway. SLAMF8 overexpression mBMSCs effectively accelerate the healing of femoral fracture in mice.

Selective Dissolution of Calcium Pyrophosphate Dihydrate Crystals Using a Pyrophosphate Specific Receptor.

Pseudo-gout is caused by the deposition of highly insoluble calcium pyrophosphate dihydrate (CPPD) crystals in the joints of sufferers. This leads to inflammation and ultimately joint damage. The insolubility of CPPD is driven by the strong attraction of di-cationic calcium ions with tetra-anionic pyrophosphate ions. One of the challenges of dissolving CPPD is that a related mineral, hydroxy apatite (HA) is present in larger amounts in the form of bone and also contains strongly interacting calcium and phosphate ions. Our aim in this work was to selectively dissolve CPPD in preference to HA. To accomplish this, we used a known receptor for pyrophosphate that contains two complexed zinc ions that are ideally spaced to interact with the tetra-anion of pyrophosphate. We hypothesized that such a molecule could act as a preorganized tetra-cation that would be able to outcompete the two calcium ions present in the crystal lattice of CPPD. We demonstrate both visually and through analysis of released phosphorous that this molecule is able to preferentially dissolve CPPD over the closely related HA and thus can form the basis for a possible approach for the treatment of pseudo-gout.

Wide & deep learning for predicting relative mineral compositions of sediment cores solely based on XRF scans, a case study from Pleistocene Paleolake Olduvai, Tanzania

This study develops a method to use deep learning models to predict the mineral assemblages and their relative abundances in paleolake cores using high-resolution XRF core scan elemental data and X-ray diffraction (XRD) mineralogical results from the same core taken at coarser resolution. It uses the XRF core scan data along with published mineralogical information from the Olduvai Gorge Coring Project (OGCP) 2014 sediment cores 1A, 2A, and 3A from Paleolake Olduvai, Tanzania. Both regression and classification models were developed using a Keras deep learning framework to assess the predictability of mineral assemblages with their relative abundances (in regression models) or at least the mineral assemblages (in classification models) using XRF core scan data. Models were created using the Sequential class and Functional API with different model architectures. The correlation matrix of element ratios calculated from XRF element intensity records from the cores and XRD-derived mineralogical information was used to select the most useful features to train the models. 1057 training data records were used for the models. Lithological classes were also used for some models using Wide & Deep neural networks since those combine the benefits of memorization and generalization for mineral prediction. The results were validated using 265 validation data records unseen by the model and discuss the accuracy of models using six test records. The optimized Deep Neural Network (DNN) classification model achieved over 86% binary accuracy while the regression models were also able to predict the relative mineral abundances of samples with high accuracies. Overall, the study shows the efficacy of a carefully crafted Deep Learning (DL) model for predicting mineral assemblages and abundances using high-resolution XRF core scan data.

Geochronology, Petrogenesis, and Metallogenic Implications of Quartz Monzonite Porphyry in the Shanlixu Copper–Gold Deposit in the Lujiang–Chuzhou Area, Middle–Lower Yangtze River Valley Metallogenic Belt, China

The Lujiang–Chuzhou Metallogenic Area is an important component of the Middle–Lower Yangtze River Valley Metallogenic Belt. Despite being an important copper–gold deposit in this area, the Shanlixu skarn Cu-Au deposit has not yet been systematically studied. According to LA-ICP-MS zircon U-Pb dating, the quartz monzonite porphyry from the Shanlixu deposit is aged 137.5 ± 1.7 Ma: while it differs from the timing of the magmatism and related mineralization in the Lujiang–Chuzhou Area, it is consistent with magmatic activity elsewhere in the Middle–Lower Yangtze River Valley Metallogenic Belt. The Ce4+/Ce3+ values of zircon in the quartz monzonite porphyry vary from 204.5 to 886.5, indicating that the intrusion might have formed in an environment with high oxygen fugacity. Additionally, the quartz monzonite porphyry exhibits high contents of Al2O3, Sr, Ba, and Mg# (Mg# = Mg2+/(Mg2+ + Fe2+)) and low ratios of Y, Nb, Ta, and K2O/Na2O, showing geochemical characteristics similar to those of adakitic rocks. Based on these characteristics, it is suggested that the intrusion might have been derived from the partial melting of subducted oceanic crust under a continental arc margin setting. Furthermore, it is strongly indicated that the quartz monzonite porphyry from the Shanlixu deposit, in the Lujiang–Chuzhou Area, is closely related to Cu-Au mineralization, as suggested by the age of the intrusion, which is approximately 137 Ma. These findings provide a new direction for research and exploration in this region.

Pulsatile extractions of Lower Cretaceous silicic volcanic plumbing system beneath the Baiyunzhang and Lianhuashan basins, eastern Guangdong: silicic magma evolution and related mineralization

Highly differentiated magmas are closely related to the formation of tin deposits. The Lianhuashan Basin and Baiyunzhang Basin, surrounded by multiple coeval tin deposits, developed various types of volcanic and subvolcanic rocks. The diagenetic connections between different types of rocks within the two basins provide new insight into the evolution of the silicic magma systems and the impact of highly differentiated magmas on tin mineralization. Both basins have consistent zircon U–Pb ages (143–138 Ma) and similar whole-rock Nd isotopes ( ε Nd ( t ) = −5.7 to −3.4) and zircon Hf–O isotope ranges ( ε Hf ( t ) = −9.0 to −2.5; δ 18 O = 5.1–7.9), suggesting that both basins originate from the same deep-level magma reservoir, followed by different degrees of crystal differentiation and several episodes of crystal–melt separation in their respective shallow-level magma reservoirs. The multiple pulses of magma extraction eventually produced different volcanic rocks (granite porphyry and rhyolite porphyry), whereas the remaining crystal mush consolidated in situ to form quartz monzonite porphyry. Further studies show that the tectonic regime changed from a compressive to an extensional environment at c . 140 Ma. Consequently, mantle-derived magmas with low oxygen fugacity injected shallow magma reservoirs that were able to evolve to a high degree of differentiation through multiple recharge, thus favouring the formation of the Sn deposit.

Formation of orthopyroxene-magnetite symplectites by reactive melt flow: Insights into the Shangzhuang layered intrusion in Beijing, China

Interstitial microstructures in layered intrusions can provide crucial insights into the formation, transport, evolution, and solidification processes of magma. The symplectites commonly observed in the Shangzhuang layered intrusions in Beijing, China, can be classified into three types based on their occurrence and related primocryst minerals. Regardless of variation in types, the vermicular symplectites consistently exhibit a volume ratio of magnetite to orthopyroxene at approximately 1:4. Orthopyroxene in the symplectites shows no geochemical difference from those primocrysts. Inter-cumulus hornblende formed during the late stage after the formation of symplectites so that the symplectites are always enclosed by hornblende. By utilizing the hornblende geothermobarometer, we have also constrained that the symplectites have been formed within a relatively wide temperature range of 1040–915 °C through a reaction between the interstitial immiscible Fe-rich melt and the primocryst olivine and orthopyroxene. The reaction can be simplified as Ol/Opx (primocryst) + Fe-rich melt → Opx (symplectite) + Mt (symplectite). Besides, based on the mass balance and reaction results, the Si/O ratio of Fe-rich melt is estimated to be 1:3. The study of these symplectites contributes to refining the processes of reactive melt flow in mafic layered intrusions during late-stage magmatic crystallization.

Integrating multispectral remote sensing and geological investigation for gold prospecting in the Borongo-Mborguene gold field, eastern Cameroon

Multispectral remote sensing data has great promise for mineral prospecting via regional-scale mapping of alteration zones and geological structures, once the method is calibrated using in-situ geological observations. The Borongo-Mborguene area, located in eastern Cameroon at the transition from sub-tropical to arid climates, hosts several alluvial gold deposits. In this investigation, maps developed by processing of Landsat-8 OLI images, ASTER satellite images, and SRTM DEM data were compared to results of a comprehensive field survey to locate zones of hydrothermal alteration and regional structural lineaments, and to verify the association of these features with gold mineralization. Specific Landsat-8 and ASTER band ratios, as well as principal component analysis of the multispectral images, were selected to isolate spectral signals that characterize particular groups of alteration minerals, such as clays, hydrated carbonates, hydrated sulphates, iron oxides, and iron hydroxides. Lineaments and their preferred orientations were extracted by filtering of the digital elevation data. A fuzzy logic approach was subsequently applied to the ensemble of resulting maps to highlight five areas of concentrated hydrothermal alteration and structural complexity as potential gold prospects (Mborguene, Boutila, Nandoungue, Borongo and Ouaden villages). Petrographic study of samples collected from the remotely-identified alteration zones revealed a hydrothermal ore assemblage of gold, galena, pyrite and hematite in mineralized quartz veins. Structural control of the alteration zones in the Borongo-Mborguene gold field was confirmed by field mapping along a shear zone. Hence, our petrographic and field studies indicate that the multispectral remote sensing data and data processing methods developed herein are appropriate for mineral exploration in remote sub-tropical areas of Africa. More generally, the computationally efficient and simple procedure developed here should yield accurate preliminary maps of the spatial distribution of hydrothermal halos and related mineral deposits in challenging mixed-type vegetated terrain around the globe.

Bone matrix properties in adults with osteogenesis imperfecta are not adversely affected by setrusumab-a sclerostin neutralizing antibody.

Osteogenesis imperfecta (OI) is a skeletal dysplasia characterized by low bone mass and frequent fractures. Children with OI are commonly treated with bisphosphonates to reduce fracture rate, but treatment options for adults are limited. In the Phase 2b ASTEROID trial, setrusumab (a sclerostin neutralizing antibody, SclAb) improved bone density and strength in adults with type I, III, and IV OI. Here, we investigate bone matrix material properties in tetracycline-labeled trans iliac biopsies from 3 groups: (1) control: individuals with no metabolic bone disease, (2) OI: individuals with OI, (3) SclAb-OI: individuals with OI after 6 mo of setrusumab treatment (as part of the ASTEROID trial). In addition to bone histomorphometry, bone mineral and matrix properties were evaluated with nanoindentation, Raman spectroscopy, second harmonic generation imaging, quantitative backscatter electron imaging, and small-angle X-ray scattering. Spatial locations of fluorochrome labels were identified to differentiate inter-label bone of the same tissue age and intra-cortical bone. No difference in collagen orientation was found between the groups. The bone mineral density distribution and analysis of Raman spectra indicate that OI groups have greater mean mineralization, greater relative mineral content, and lower crystallinity than the control group, which was not altered by SclAb treatment. Finally, a lower modulus and hardness were measured in the inter-label bone of the OI-SclAb group compared to the OI group. Previous studies suggest that even though bone from OI has a higher mineral content, the extracellular matrix (ECM) has comparable mechanical properties. Therefore, fragility in OI may stem from contributions from other yet unexplored aspects of bone organization at higher length scales. We conclude that SclAb treatment leads to increased bone mass while not adversely affecting bone matrix properties in individuals with OI.

Constraining the evolutionary stages of a hypogene karst system by combining morphological, geochemical and geochronological data - the example of carbonate breccia-hosted Melnička Peštera

A combination of morphological observations, geochemical data from calcite minerals and geochronology by burial age dating and U-series is used to constrain the geological and geomorphological setting and the evolutionary stages of a hypogene karst system. This methodological suit is applied to Melnička Peštera, a horizontal cave developed in carbonate breccia overlying dolomite marble in Melnica locality (N. Macedonia), where hydrothermal karst development occurred in both dolomite and calcite marble. The passage morphology of the cave, having a reverse triangle, Laughöhle cross-sections, suggests development near the water table by slowly moving waters. Calcite crusts are found throughout the cave, and based on their relationship to passage morphology, appear to pre-date main horizontal passage formation. Their carbonate stable and clumped isotope and fluid inclusion noble gas compositions indicate cooling of the hydrothermal system with an increased contribution of shallower groundwater. U-series data suggests Early Pleistocene deposition of the calcite crusts. Water table notches and convectional features carved into breccia bedrock and calcite crusts point to subsequent development at and above the water table by condensation corrosion. The solutional aggressiveness near the water table was likely related to CO2, that previously degassed from the deeper parts of the system where calcite was depositing, and redissolved in the cooler, shallower waters. Due to poor connection with the surface, the cave air above the water table likely had high pCO2, that further helped to maintain aggressiveness of the groundwater at the water-air contact, and boosted condensation corrosion above it, preventing deposition of related secondary calcite minerals. The cave-hosting carbonate breccia deposited as an alluvial fan filling up a paleovalley cut into Upper Miocene sediments. Cosmogenic nuclide burial age dating of quartz fragments confirms Early Pliocene age for the breccia, and constrains the paleovalley incision to Late Miocene, likely related to base level lowering caused by the Messinian Salinity Crisis.

Geochronology, geochemistry, and isotope signatures of porphyries from the dabate Mo—Cu deposit, Western Tianshan, China: Implications for petrogenesis and geodynamic setting

The Dabate deposit in the West Tianshan Orogenic Belt is a large porphyry Mo-Cu deposit with obvious zoning feature. The Dabate pluton is closely related to mineralization associated with the rhyolite and granite porphyries. Copper (Cu) mineralization occurs on the margin of the rhyolite porphyry, and molybdenum (Mo) mineralization occurs in the interior of the rhyolite porphyry. Petrology, zircon U-Pb isotopic data, whole-rock geochemistry, and Sr-Nb-Hf-Pb isotopic data of the rhyolite and granite porphyries in the Dabate Mo-Cu mining zone and to discuss the properties, sources, evolution, and tectonic environment of the magma. Zircon U-Pb age dating shows that the rhyolite porphyry and granite porphyry were formed in 300.1 ± 1.3 Ma and 290.4 ± 5.2 Ma, respectively, and they are geochemically similar. Both are characterized by negative Eu anomalies (δEu = 0.09–0.15 and 0.10–0.11, respectively) and are slightly rich in light rare earth elements (LREE) but depleted in high-field-strength elements (HFSE), which indicates that they are both A2 type granites that underwent high differentiation. The Sr isotope (ISr) values for the rhyolite and granite porphyries range from 0.70564 to 0.70658 and 0.70833–0.70954, respectively. The Nd isotopic composition [εNd(t)] values for both are negative but close to zero (−0.25 to −0.46 and −0.65 to −1.10, respectively), and the two-stage depleted mantle Nd model ages (TDM2(Nd)) are 1.07–1.10 Ga and 1.11–1.14 Ga, respectively. Zircon εHf(t) values are 7.29–11.97 and 6.26–11.08 for rhyolite porphyry and granite porphyry, respectively, and the two-stage Hf model ages (TDM2(Hf)) are 550–848 Ma and 605–916 Ma, respectively. The initial Pb isotope ratios for the rhyolite and granite porphyry are close at (206Pb/204Pb)i = 18.26–18.65, (207Pb/204Pb)i = 15.54–15.64, and (208Pb/204Pb)i = 38.19–38.57. These results indicate that the two porphyries have a mixed source, likely originating from the partial melting of mantle blended with some recently formed lower crust material. The geochronology, geochemistry, and Sr-Nd-Hf-Pb isotope data of existing intrusions in the West Tianshan imply that the Late Carboniferous to Early Permian Dabate area was underplated in a post-collisional extensional setting, and A2-type granite intrusions with related Mo-Cu mineralization were formed.

Li-mineralized pegmatite of anatectic origin: Constraints from Li[sbnd]Hf isotopes and geochemical modeling

Pegmatites are important reservoirs of lithium resources. There is an ongoing debate as to whether Li-mineralized pegmatites were generated from evolved granitic systems via extreme differentiation or by direct melting of metasedimentary rocks. The Chinese Altay is one of the largest pegmatite provinces in the world, and includes many rare-metal pegmatites (e.g., Koktokay, Kelumute, Kaluan and Azubai). However, they display significant differences in formation ages and isotopic compositions compared with the neighbouring or potential parental granites. In this contribution, we present a case study of the Kaluan Li ore deposit in the Chinese Altay, elucidating the origins of pegmatites and related Li mineralization. The Kaluan Li-mineralized pegmatites are characterized by high SiO2, K2O, Na2O, Li, Cs, Ta, and Rb contents; low Fe2O3T, MgO, Ba, and Sr contents; and peraluminous signatures. They have homogeneous HfLi isotopic compositions (εHf (t) = −0.6 to +2.5; δ7Li = +1.6 to +5.8‰) that are within the range of HfLi isotopic compositions of the Kulumuti Group schists (εHf (t) = −2.8 to +7.5; δ7Li = −8.6 to +10.8‰). In addition, the chemical compositions of the melt derived from the partial melting of the Kulumuti Group by phase equilibrium modeling are compatible with our analyses of the Kaluan Li-mineralized pegmatites. These similarities suggest that the Kaluan Li-mineralized pegmatites were derived from the partial melting of the Kulumuti Group schists at depths during the Triassic, in a post-orogenic and extensional setting. The generation of these pegmatites was mostly controlled by biotite dehydration melting at relatively high temperatures, rather than by the low-temperature melting of muscovite. Trace elements modeling results show that approximately 33–36% partial melting of the average Kulumuti Group schist may produce melts with maximum Li concentrations ranging from 664 to 751 ppm. Subsequently, a high degree of fractionation exceeding 85%, was required for the Li concentration of the residual melt to reach concentrations suitable for crystallization into albite-spodumene pegmatites. Based on our research, an anatectic origin model may have general applicability in explaining the genesis and mineralization of rare-metal pegmatites in the Chinese Altay.

Exogenous GABA Enhances Copper Stress Resilience in Rice Plants via Antioxidant Defense Mechanisms, Gene Regulation, Mineral Uptake, and Copper Homeostasis.

The importance of gamma-aminobutyric acid (GABA) in plants has been highlighted due to its critical role in mitigating metal toxicity, specifically countering the inhibitory effects of copper stress on rice plants. This study involved pre-treating rice plants with 1 mM GABA for one week, followed by exposure to varying concentrations of copper at 50 μM, 100 μM, and 200 μM. Under copper stress, particularly at 100 μM and 200 μM, plant height, biomass, chlorophyll content, relative water content, mineral content, and antioxidant activity decreased significantly compared to control conditions. However, GABA treatment significantly alleviated the adverse effects of copper stress. It increased plant height by 13%, 18%, and 32%; plant biomass by 28%, 52%, and 60%; chlorophyll content by 12%, 30%, and 24%; and relative water content by 10%, 24%, and 26% in comparison to the C50, C100, and C200 treatments. Furthermore, GABA treatment effectively reduced electrolyte leakage by 11%, 34%, and 39%, and the concentration of reactive oxygen species, such as malondialdehyde (MDA), by 9%, 22%, and 27%, hydrogen peroxide (H2O2) by 12%, 38%, and 30%, and superoxide anion content by 8%, 33, and 39% in comparison to C50, C100, and C200 treatments. Additionally, GABA supplementation led to elevated levels of glutathione by 69% and 80%, superoxide dismutase by 22% and 125%, ascorbate peroxidase by 12% and 125%, and catalase by 75% and 100% in the C100+G and C200+G groups as compared to the C100 and C200 treatments. Similarly, GABA application upregulated the expression of GABA shunt pathway-related genes, including gamma-aminobutyric transaminase (OsGABA-T) by 38% and 80% and succinic semialdehyde dehydrogenase (OsSSADH) by 60% and 94% in the C100+G and C200+G groups, respectively, as compared to the C100 and C200 treatments. Conversely, the expression of gamma-aminobutyric acid dehydrogenase (OsGAD) was downregulated. GABA application reduced the absorption of Cu2+ by 54% and 47% in C100+G and C200+G groups as compared to C100, and C200 treatments. Moreover, GABA treatment enhanced the uptake of Ca2+ by 26% and 82%, Mg2+ by 12% and 67%, and K+ by 28% and 128% in the C100+G and C200+G groups as compared to C100, and C200 treatments. These findings underscore the pivotal role of GABA-induced enhancements in various physiological and molecular processes, such as plant growth, chlorophyll content, water content, antioxidant capacity, gene regulation, mineral uptake, and copper sequestration, in enhancing plant tolerance to copper stress. Such mechanistic insights offer promising implications for the advancement of safe and sustainable food production practices.