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22 pages, 9337 KB  
Article
Subducting Slab—Upper Plate Configuration, and Three-Dimensional Thermal Structure of Central-Southern Peru
by Antonella Megna, Stefano Mazzoli and Stefano Santini
Geosciences 2026, 16(6), 216; https://doi.org/10.3390/geosciences16060216 - 30 May 2026
Viewed by 272
Abstract
The study investigates the three-dimensional architecture and thermal structure of the Central Andes in centralsouthern Peru, highlighting the interplay between basement structure, Moho geometry, slab configuration, and thermal properties. Basement structural highs and lows acted as zones of weakness that localized deformation during [...] Read more.
The study investigates the three-dimensional architecture and thermal structure of the Central Andes in centralsouthern Peru, highlighting the interplay between basement structure, Moho geometry, slab configuration, and thermal properties. Basement structural highs and lows acted as zones of weakness that localized deformation during Andean shortening. The Moho exhibits significant lateral heterogeneity, reflecting the combined effects of subduction processes, crustal shortening, magmatic underplating, and lower crustal flow or delamination. Its geometry provides key constraints on crustal thickness, seismic structure, and lithospheric dynamics. The subducting Nazca Plate shows strong along-strike variations in dip and continuity, influenced by plate kinematics and features such as the Nazca Ridge. These variations control mantle wedge development, arc magmatism, and deformation patterns in the overriding plate, contributing to the segmentation of the Andes. Steepslab segments promote mantle melting and volcanic activity, whereas flat-slab regions suppress magmatism. Consistent with these tectonic controls, Qs values increase from northwest to southeast, reflecting a transition from flat-slab conditions with low heat flow and limited geothermal activity to steep subduction zones characterized by active magmatism, elevated heat flow, and significant geothermal potential. This spatial variation underscores the strong coupling between slab geometry, thermal structure, and surface geothermal expression. Full article
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21 pages, 1236 KB  
Review
A Review of H2 Generation and H2O Distribution in the Earth’s Interior
by Yankun Jian, Haiying Hu, Wenqing Sun, Song Luo, Pengfei Wang, Liping Wang, Jinlong Zhu, Songbai Han and Lidong Dai
Minerals 2026, 16(5), 507; https://doi.org/10.3390/min16050507 - 12 May 2026
Viewed by 408
Abstract
Hydrogen (H) is the most abundant element in the solar system. In the Earth’s interior, it primarily exists in the form of hydrogen gas, water, atomic hydrogen, and hydroxyl groups. Hydrogen gas, as a clean energy source, is widely distributed within the Earth [...] Read more.
Hydrogen (H) is the most abundant element in the solar system. In the Earth’s interior, it primarily exists in the form of hydrogen gas, water, atomic hydrogen, and hydroxyl groups. Hydrogen gas, as a clean energy source, is widely distributed within the Earth and is mainly generated through serpentinization, with minor contributions from water radiolysis, rock fracturing, biological activity, etc. Hydrogen sequestration occurs mainly through clay adsorption, entrapment under rock layers, dissolution in water, and fluid inclusions. Besides being present as pore water, hydrogen in the deep Earth predominantly resides in minerals as point defects related to hydrogen species (e.g., OH, H+). During the Earth’s evolution, substantial hydrogen was stored in the deep Earth through accretion, and surface water has been transported into the Earth’s interior via subducting slabs; meanwhile, it can migrate upward through magmatic activity and mantle plumes. The inputs and outputs constitute the global hydrogen cycle. Hydrogen concentration and distribution are highly heterogeneous across the crust, mantle and core. The upper mantle is likely mostly dry, while the Earth’s core is potentially a large reservoir of hydrogen. Small amounts of hydrogen can profoundly influence the physicochemical properties of the Earth’s interior materials, as well as the dynamic processes within the Earth’s interior. Full article
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11 pages, 1850 KB  
Article
Preliminary Descriptive Characterization Reveals Physicochemical Differentiation of Tissue Mucus in Crassostrea gigas
by Shiyu Cui, Xiutong Wang, Na Liu and Xixi Wang
Materials 2026, 19(10), 1912; https://doi.org/10.3390/ma19101912 - 7 May 2026
Viewed by 298
Abstract
Marine biomucus, a complex biomolecular gel, plays a pivotal role in defense against biofouling, mitigation of environmental stress, and regulation of biomineralization. This study conducts a comparative analysis of the physicochemical properties of mucus secreted by three distinct tissues—labial palps, mantle, and gills—of [...] Read more.
Marine biomucus, a complex biomolecular gel, plays a pivotal role in defense against biofouling, mitigation of environmental stress, and regulation of biomineralization. This study conducts a comparative analysis of the physicochemical properties of mucus secreted by three distinct tissues—labial palps, mantle, and gills—of the Pacific oyster (Crassostrea gigas), alongside their freeze-dried counterparts. By integrating amino acid profiling, scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR), we explored potential correlations between chemical composition, microstructure, and hypothesized macroscopic functional properties. Our findings inspire distinct tissue-specific structural characteristics that suggest potential structure–function relationships: The structure of labial palps mucus leads to the hypothesis that it may act as a viscous barrier-like property; mantle mucus shows features that could potentially support the formation of continuous films by a dense hydrogen-bond network; and gill mucus exhibits a porous three-dimensional network that potentially facilitates the process of respiratory and feeding. This work not only explores the material basis and potential structure–function relationships of C. gigas mucus as a natural biopolymer but also provides a potential theoretical framework for the design of novel marine-inspired biomimetic materials. Full article
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23 pages, 19492 KB  
Article
Geochemical Compositions of Zircon and Apatite from the Langdu Intrusions in the Zhongdian Arc: Implications for Porphyry–Skarn Cu Mineralization
by Lei Mo, Chengbiao Leng, Hongze Gao, Kaixuan Li, Xilian Chen, Yanjun Wang, Tao Dong, Wanquan Luo and Haijun Yu
Minerals 2026, 16(4), 413; https://doi.org/10.3390/min16040413 - 16 Apr 2026
Viewed by 411
Abstract
The Zhongdian Arc is an important copper polymetallic ore cluster in China’s Sanjiang Tethyan Metallogenic Domain, and the Langdu deposit is a representative porphyry–skarn Cu deposit in this region. This study aims to constrain the timing of magmatic activity at the Langdu deposit. [...] Read more.
The Zhongdian Arc is an important copper polymetallic ore cluster in China’s Sanjiang Tethyan Metallogenic Domain, and the Langdu deposit is a representative porphyry–skarn Cu deposit in this region. This study aims to constrain the timing of magmatic activity at the Langdu deposit. It also seeks to reveal the magma’s physical–chemical properties and evolution, and to identify the factors controlling mineralization. To achieve these objectives, this study used LA-ICP-MS zircon U-Pb dating and elemental analysis, combined with halogen and trace element data from apatite. Zircon U–Pb dating shows that the Langdu intrusions were emplaced at ca. 216 Ma in a continental arc setting associated with the westward subduction of the Garzê–Litang oceanic crust during the Late Triassic. Geochemical and mineralogical features indicate that the Langdu intrusions are I-type granite. They originated from partial melting of the mantle wedge metasomatized by subduction fluids. During their ascent, these magmas experienced fractional crystallization dominated by amphibole, titanite, rutile, and monazite. Geochemical records from zircon and apatite further reveal that the ore-forming magma of the Langdu intrusions exhibited high oxygen fugacity (ΔFMQ = +1.53), elevated H2O content (avg. 7.63 wt.%), and enrichment in S (avg. 560 ppm) and Cl (avg. 2141 ppm). This Cl-rich magma experienced fluid exsolution during its early evolutionary stage. This provided the necessary conditions for metal extraction and transport. In summary, the key factors controlling the formation of the Langdu porphyry–skarn Cu deposit are high-oxygen-fugacity magma enriched in water and volatiles (S and Cl), coupled with efficient fluid exsolution. This understanding is important for better understanding regional metallogeny and for guiding mineral exploration. Full article
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24 pages, 29496 KB  
Article
Terrestrial Heat Flow and Crustal Thermal Structure of the Tazhong Uplift, Tarim Basin, Northwest China
by Chunlong Yang, Ming Cheng, Yurun Rui, Jin Su, Ke Zhang, Qing Zhao, Baoyi Chen, Yunzhan Li and Yuyang Liu
Processes 2026, 14(6), 980; https://doi.org/10.3390/pr14060980 - 19 Mar 2026
Viewed by 387
Abstract
Geothermal field characteristics fundamentally control hydrocarbon generation, phase evolution, and preservation, and are particularly critical in deep to ultra-deep hydrocarbon exploration. The Tazhong Uplift is a key area for deep to ultra-deep hydrocarbon exploration in the Tarim Basin; however, its deep thermal regime [...] Read more.
Geothermal field characteristics fundamentally control hydrocarbon generation, phase evolution, and preservation, and are particularly critical in deep to ultra-deep hydrocarbon exploration. The Tazhong Uplift is a key area for deep to ultra-deep hydrocarbon exploration in the Tarim Basin; however, its deep thermal regime and controlling factors remain inadequately characterized. This study aims to accurately characterize the geothermal field and crustal thermal structure of the Tazhong Uplift to provide thermal constraints for ultra-deep exploration. We systematically compiled system steady-state temperature data from 24 wells, bottom-hole temperature (BHT) data from 51 wells, and rock thermal property measurements. Using the one-dimensional steady-state heat conduction equation, present-day geothermal gradients at 0–5000 m depths and terrestrial heat flow were calculated, and formation temperatures were predicted at deep horizons (6000–10,000 m). Results show geothermal gradients at 0–5000 m of 18.5–26.7 °C/km (average 23.06 °C/km) and heat flow of 39.3–59.8 mW/m2 (average 48.1 mW/m2), both significantly higher than basin averages. The distribution of the geothermal field is jointly controlled by basement structure and rock thermophysical properties. Basement highs typically exhibit elevated geothermal gradients and high heat flow. The dual-layer structure of “upper clastic rocks (low thermal conductivity, high heat production) + lower carbonate rocks (high thermal conductivity, low heat production)” results in a vertical differentiation characterized by a “high-upper, low-lower” geothermal gradient. Notably, the thick Upper Ordovician mudstone acts as a regional “thermal blanket”, significantly reducing geothermal parameters in the northern slope area. Crustal thermal structure analysis indicates a “cold mantle” signature of cratonic basins, with a thermal lithosphere thickness of ~134–145 km and a Moho temperature of ~581 °C. These findings reveal that despite the ultra-deep burial (>8000 m), the “cold” thermal background and the thermal regulation of the overlying diverse lithologies maintain formation temperatures within a range favorable for liquid hydrocarbon preservation, significantly expanding the depth limit for oil exploration in the Tarim Basin. Full article
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25 pages, 26724 KB  
Article
Construction of an In Vitro Blood–Brain Barrier Micro-Organoid Model Using Decellularized Squid Mantle Scaffold Film
by Haoyu Sun, Xiaozhen Diao, Jiali Feng, Huiying Wang, Jeevithan Elango and Wenhui Wu
J. Funct. Biomater. 2026, 17(2), 106; https://doi.org/10.3390/jfb17020106 - 23 Feb 2026
Cited by 2 | Viewed by 1534
Abstract
Although blood–brain barrier (BBB) models are of great value in investigating neurological diseases, the structural complexity and intricate function based on cell–cell interactions of the BBB bring various limitations to the applications of existing models. In this study, a novel BBB micro-organoid model [...] Read more.
Although blood–brain barrier (BBB) models are of great value in investigating neurological diseases, the structural complexity and intricate function based on cell–cell interactions of the BBB bring various limitations to the applications of existing models. In this study, a novel BBB micro-organoid model was established by culturing neurovascular unit (NVU) cells on a decellularized squid mantle scaffold (DSMS) film to reconstitute a more authentic and reliable NVU microenvironment for in vitro research. The DSMS applied was obtained from squid mantle scaffolds via decellularization, followed by defatting, and showed good biocompatibility with no cytotoxicity. The DSMS film was finally prepared by lyophilization. The lyophilized film exhibited a void ratio and pore size suitable for the adhesion and growth of endothelial cells (hCMEC/D3) and astrocytes (hACs), which led to the formation of a BBB-like spatial structure. The BBB micro-organoid model exhibited functional barrier properties, including an effective transendothelial electrical resistance (TEER) of approximately 230 Ω/cm2, restricted permeability to macromolecules—with apparent permeability coefficients (Papp) of 6.3 × 10−7 cm/s for 10 kDa and 2.7 × 10−7 cm/s for 70 kDa FITC–dextran—and expression of tight junctional complex (TJC) proteins such as vascular endothelial cadherin (VE-cad) and Zonula Occludens-1 (ZO-1). Furthermore, low-density lipoprotein receptor-related protein 1 (LRP1), a key receptor stably expressed in these two NVU cell types, was utilized as a critical indicator to assess the integrity of the BBB micro-organ model and its responsiveness to pathophysiological stimuli, particularly under thrombotic conditions. This study not only validates the feasibility of constructing a functionally competent BBB micro-organ model using DSMS films integrated with NVU cells but also provides a promising in vitro platform for subsequent studies on the BBB-related pathological mechanisms and the evaluation of drug permeability across the BBB. Full article
(This article belongs to the Special Issue Novel Biomaterials for Tissue Engineering)
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30 pages, 4217 KB  
Review
Overview of Platinum Group Minerals (PGM): A Statistical Perspective and Their Genetic Significance
by Federica Zaccarini, Giorgio Garuti, Maria Economou-Eliopoulos, John F. W. Bowles, Hannah S. R. Hughes, Jens C. Andersen and Saioa Suárez
Minerals 2026, 16(1), 108; https://doi.org/10.3390/min16010108 - 21 Jan 2026
Viewed by 1984
Abstract
The six platinum group elements (PGE) are among the rarest elements in the upper continental crust of the earth. Higher values of PGE have been detected in the upper mantle and in chondrite meteorites. The PGE are siderophile and chalcophile elements and are [...] Read more.
The six platinum group elements (PGE) are among the rarest elements in the upper continental crust of the earth. Higher values of PGE have been detected in the upper mantle and in chondrite meteorites. The PGE are siderophile and chalcophile elements and are divided into the following: (1) the Ir subgroup (IPGE) = Os, Ir, and Ru and (2) the Pd subgroup (PPGE) = Rh, Pt, and Pd. The IPGE are more refractory and less chalcophile than the PPGE. High concentrations of PGE led, in rare cases, to the formation of mineral deposits. The PGE are carried in discrete phases, the platinum group minerals (PGM), and are included as trace elements into the structure of base metal sulphides (BM), such as pentlandite, chalcopyrite, pyrite, and pyrrhotite. Similarly to PGE, the PGM are also divided into two main groups, i.e., IPGM composed of Os, Ir, and Ru and PPGM containing Rh, Pt, and Pd. The PGM occur both in mafic and ultramafic rocks and are mainly hosted in stratiform reefs, sulphide-rich lenses, and placer deposits. Presently, there are only 169 valid PGM that represent about 2.7% of all 6176 minerals discovered so far. However, 496 PGM are listed among the valid species that have not yet been officially accepted, while a further 641 are considered as invalid or discredited species. The main reason for the incomplete characterization of PGM resides in their mode of occurrence, i.e., as grains in composite aggregates of a few microns in size, which makes it difficult to determine their crystallography. Among the PGM officially accepted by the IMA, only 13 (8%) were discovered before 1958, the year when the IMA was established. The highest number of PGM was discovered between 1970 and 1979, and 99 PGM have been accepted from 1980 until now. Of the 169 PGM accepted by the IMA, 44% are named in honour of a person, typically a scientist or geologist, and 31% are named after their discovery localities. The nomenclature of 25% of the PGM is based on their chemical composition and/or their physical properties. PGM have been discovered in 25 countries throughout the world, with 64 from Russia, 17 from Canada and South Africa (each), 15 from China, 12 from the USA, 8 from Brazil, 6 from Japan, 5 from Congo, 3 from Finland and Germany (each), 2 from the Dominican Republic, Greenland, Malaysia, and Papua New Guinea each, and only 1 from Argentine, Australia, Bulgaria, Colombia, Czech Republic, England, Ethiopia, Guyana, Mexico, Serbia, and Tanzania each. Most PGM phases contain Pd (82 phases, 48% of all accepted PGM), followed, in decreasing order of abundances, by those of Pt 35 phases (21%), Rh 23 phases (14%), Ir 18 phases (11%), Ru 7 phases (4%), and Os 4 phases (2%). The six PGE forming the PGM are bonded to other elements such as Fe, Ni, Cu, S, As, Te, Bi, Sb, Se, Sn, Hg, Ag, Zn, Si, Pb, Ge, In, Mo, and O. Thirty-two percent of the 169 valid PGM crystallize in the cubic system, 17% are orthorhombic, 16% hexagonal, 14% tetragonal, 11% trigonal, 3% monoclinic, and only 1% triclinic. Some PGM are members of a solid-solution series, which may be complete or contain a miscibility gap, providing information concerning the chemical and physical environment in which the mineral was formed. The refractory IPGM precipitate principally in primitive, high-temperature, mantle-hosted rocks such as podiform and layered chromitites. Being more chalcophile, PPGE are preferentially collected and concentrated in an immiscible sulphide liquid, and, under appropriate conditions, the PPGM can precipitate in a thermal range of about 900–300 °C in the presence of fluids and a progressive increase of oxygen fugacity (fO2). Thus, a great number of Pt and Pd minerals have been described in Ni-Cu sulphide deposits. Two main genetic models have been proposed for the formation of PGM nuggets: (1) Detrital PGM represent magmatic grains that were mechanically liberated from their primary source by weathering and erosion with or without minor alteration processes, and (2) PGM reprecipitated in the supergene environment through a complex process that comprises solubility, the leaching of PGE from the primary PGM, and variation in Eh-pH and microbial activity. These two models do not exclude each other, and alluvial deposits may contain contributions from both processes. Full article
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19 pages, 13161 KB  
Article
Zircon U–Pb Ages and Geochemistry of Diaoluoshan Granite, Hainan Island: Implications for Late Cretaceous Tectonics in South China
by Chao Wang, Dingyong Liang, Changxin Wei, Mulong Chen, Zailong Hu and Changyan Lv
Minerals 2025, 15(12), 1242; https://doi.org/10.3390/min15121242 - 24 Nov 2025
Cited by 1 | Viewed by 1301
Abstract
Hainan Island has experienced a superposition of multiple phases of tectonic movements and magmatic activities, leading to numerous controversies regarding the genesis, spatiotemporal distribution, and tectonic setting of its Yanshanian granites. Accurately determining the characteristics of magmatic rocks during this period is crucial [...] Read more.
Hainan Island has experienced a superposition of multiple phases of tectonic movements and magmatic activities, leading to numerous controversies regarding the genesis, spatiotemporal distribution, and tectonic setting of its Yanshanian granites. Accurately determining the characteristics of magmatic rocks during this period is crucial for clarifying the regional tectonic evolution. This study focuses on Diaoluoshan granite in the southeastern part of Hainan Island. Through petrological, mineralogical, zircon U-Pb geochronological, and geochemical analyses, it aims to identify the genetic type, formation age, and magma source properties of this pluton, thereby revealing the Late Yanshanian tectonic setting of Hainan Island. The results show that the zircon U-Pb dating of Diaoluoshan granite yields an age of 102.5 ± 2.8Ma, indicating its formation in the late Early Cretaceous. This granite is a high-K calc-alkaline I-type granite, with silica (SiO2) content ranging from 63.9% to 77.3%. The pluton exhibits significant negative anomalies of Ta, Nb, P, and Ti, as well as relatively obvious positive anomalies of Rb, Th, U, and K. The biotite in the granite has a magnesium oxide (MgO) content ranging from 12.84% to 13.13%, showing characteristics of crust–mantle material mixing. The magma of this pluton was derived from the partial melting of the lower continental crust mixed with the uprising and underplating mantle mafic magmas, driven by the subduction of the Paleo-Pacific Plate and its slab rollback. This study confirms that during the Late Yanshanian, Hainan Island was in an extensional rift environment driven by the subduction of the Paleo-Pacific Plate and its slab rollback, but without a well-developed volcanic front. It provides key geological evidence for the study of Yanshanian tectono-magmatic evolution in South China. Full article
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27 pages, 13959 KB  
Article
Petrogenesis of Tholeiitic Basalts from CZK06 Drill Core on the Tianchi Volcano, China–North Korea Border
by Cheng Qian, Jintao Ge, Bo Pan, Zhen Tang, Bin Jiang, Tianri Cui and Lu Lu
Minerals 2025, 15(9), 949; https://doi.org/10.3390/min15090949 - 5 Sep 2025
Viewed by 1153
Abstract
To constrain Tianchi Volcano basalt petrogenesis, this study focuses on tholeiitic basalts from the CZK06 drill core on the northern slope. Using elemental geochemistry and Mg isotope analyses, we investigate magma evolution, petrogenesis, and mantle source properties. The tholeiitic basalts formed during the [...] Read more.
To constrain Tianchi Volcano basalt petrogenesis, this study focuses on tholeiitic basalts from the CZK06 drill core on the northern slope. Using elemental geochemistry and Mg isotope analyses, we investigate magma evolution, petrogenesis, and mantle source properties. The tholeiitic basalts formed during the Pliocene-Early Pleistocene shield-forming stage, recording three stages of basaltic volcanism (Phases I to III). Classified as sodium-series basalts, they exhibit geochemical affinities with EM1-type OIB. Their δ26Mg values (−0.420‰ to −0.150‰) show a substantially wider range than N-MORB. Their geochemical compositions are primarily controlled by source region characteristics and partial melting degree, with minor additional influences from fractional crystallization and crustal contamination. Fractional crystallization intensity shows a progressive increase from Phase I to III. Integrated with geochemical tracing studies of Changbaishan basalts, we propose that the tholeiitic basalts are derived predominantly from the partial melting of carbonatized pyroxenite, which originated from subducted ancient clay-rich altered oceanic crust. The carbonate melts driving the carbonatization were generated by low-pressure melting of recent oceanic sediments, transported by the deeply subducted carbonate-rich Pacific Plate within the Mantle Transition Zone. The tholeiitic magma formed in the Low-Velocity Zone at depths of 160–180 km beneath the lithospheric mantle. Full article
(This article belongs to the Special Issue Selected Papers from the 7th National Youth Geological Congress)
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14 pages, 2825 KB  
Article
Effects of Pressure on Hydrogen Diffusion Behaviors in Corundum
by Shun-Feng Yan, Lin Li, Xiao Dong, Xiao-Wei Li, Mao-Wen Yuan and Sheng-Rong Li
Crystals 2025, 15(8), 672; https://doi.org/10.3390/cryst15080672 - 23 Jul 2025
Viewed by 1195
Abstract
Hydrogen, as the smallest atom and a key component of water, can penetrate minerals in various forms (e.g., atoms, molecules), significantly influencing their properties. The hydrogen diffusion behavior in corundum (α-Al2O3) under high pressure was systematically investigated using the [...] Read more.
Hydrogen, as the smallest atom and a key component of water, can penetrate minerals in various forms (e.g., atoms, molecules), significantly influencing their properties. The hydrogen diffusion behavior in corundum (α-Al2O3) under high pressure was systematically investigated using the DFT + NEB method. The results indicate that H atoms tend to aggregate into H2 molecules within corundum under both ambient and high-pressure conditions. However, hydrogen predominantly migrates in its atomic form (H) under both low- and high-pressure environments. The energy barriers for H and H2 diffusion increase with pressure, and hydrogen diffusion weakens the chemical bonds nearby. Using the Arrhenius equation, we calculated the diffusion coefficient of H in corundum, which increases with temperature but decreases with pressure. On geological time scales, hydrogen diffusion is relatively slow, potentially resulting in a heterogeneous distribution of water in the lower mantle. These findings provide novel insights into hydrogen diffusion mechanisms in corundum under extreme conditions, with significant implications for hydrogen behavior in mantle minerals at high pressures. Full article
(This article belongs to the Section Inorganic Crystalline Materials)
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31 pages, 4555 KB  
Article
The Roles of Transcrustal Magma- and Fluid-Conducting Faults in the Formation of Mineral Deposits
by Farida Issatayeva, Auez Abetov, Gulzada Umirova, Aigerim Abdullina, Zhanibek Mustafin and Oleksii Karpenko
Geosciences 2025, 15(6), 190; https://doi.org/10.3390/geosciences15060190 - 22 May 2025
Cited by 1 | Viewed by 2413
Abstract
In this article, we consider the roles of transcrustal magma- and fluid-conducting faults (TCMFCFs) in the formation of mineral deposits, showing the importance of deep sources of heat and hydrothermal solutions in the genesis and history of deposit formation. As a result of [...] Read more.
In this article, we consider the roles of transcrustal magma- and fluid-conducting faults (TCMFCFs) in the formation of mineral deposits, showing the importance of deep sources of heat and hydrothermal solutions in the genesis and history of deposit formation. As a result of the impact on the lithosphere of mantle plumes rising along TCMFCFs, intense block deformations and tectonic movements are generated; rift systems, and volcanic–plutonic belts spatially combined with them, are formed; and intrusive bodies are introduced. These processes cause epithermal ore formation as a consequence of the impact of mantle plumes rising along TCMFCF to the lithosphere. At hydrocarbon fields, they play extremely important roles in conductive and convective heat, as well as in mass transfer to the area of hydrocarbon generation, determining the relationship between the processes of lithogenesis and tectogenesis, and activating the generation of hydrocarbons from oil and gas source rock. Detection of TCMFCFs was carried out using MMSS (the method of microseismic sounding) and MTSM (the magnetotelluric sounding method), in combination with other geological and geophysical data. Practical examples are provided for mineral deposits where subvertical transcrustal columns of increased permeability, traced to considerable depths, have been found; the nature of these unique structures is related to faults of pre-Paleozoic emplacement, which determined the fragmentation of the sub-crystalline structure of the Earth and later, while developing, inherited the conditions of volumetric fluid dynamics, where the residual forms of functioning of fluid-conducting thermohydrocolumns are granitoid batholiths and other magmatic bodies. Experimental modeling of deep processes allowed us to identify the quantum character of crystal structure interactions of minerals with “inert” gases under elevated thermobaric conditions. The roles of helium, nitrogen, and hydrogen in changing the physical properties of rocks, in accordance with their intrastructural diffusion, has been clarified; as a result of low-energy impact, stress fields are formed in the solid rock skeleton, the structures and textures of rocks are rearranged, and general porosity develops. As the pressure increases, energetic interactions intensify, leading to deformations, phase transitions, and the formation of chemical bonds under the conditions of an unstable geological environment, instability which grows with increasing gas saturation, pressure, and temperature. The processes of heat and mass transfer through TCMFCFs to the Earth’s surface occur in stages, accompanied by a release of energy that can manifest as explosions on the surface, in coal and ore mines, and during earthquakes and volcanic eruptions. Full article
(This article belongs to the Section Geophysics)
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36 pages, 16597 KB  
Article
Geochemistry, Isotope Characteristics, and Evolution of the Kesikköprü Iron Deposit (Türkiye)
by Erkan Yılmazer and Mustafa Haydar Terzi
Minerals 2025, 15(5), 528; https://doi.org/10.3390/min15050528 - 15 May 2025
Cited by 2 | Viewed by 2436
Abstract
The Kesikköprü iron deposit, located in the Central Anatolian Crystalline Complex, occurs in the triple contact of Kesikköprü granitoid, mafic–ultramafic rocks, and marble. The causative Kesikköprü granitoid, consisting of diorite, granodiorite, and granite, is classified as sub-alkaline, calc-alkaline, and shoshonitic, displaying metaluminous to [...] Read more.
The Kesikköprü iron deposit, located in the Central Anatolian Crystalline Complex, occurs in the triple contact of Kesikköprü granitoid, mafic–ultramafic rocks, and marble. The causative Kesikköprü granitoid, consisting of diorite, granodiorite, and granite, is classified as sub-alkaline, calc-alkaline, and shoshonitic, displaying metaluminous to partially peraluminous properties. Sr-Nd isotope data and the geochemical characteristics of the Kesikköprü granitoid indicate a metasomatized mantle origin, with its ultimate composition arising from crustal contamination and magma mixing along with fractional crystallization in a post-collisional setting. The 40Ar/39Ar geochronology reveals a total fusion age of 73.41 ± 0.32 Ma for the biotite of the Kesikköprü granitoid. The alteration pattern in the deposit is characterized by an endoskarn zone comprising garnet–pyroxene (±phlogopite ± epidote) and an exoskarn zone displaying a zoning of garnet (±pyroxene ± phlogopite), pyroxene (±garnet ± phlogopite ± epidote), epidote–garnet, and epidote-rich subzones. Magnetite is extracted from massive lenses within the exoskarn zones and shows vein, disseminated, banded, massive, and brecciated textures. The low potassium content of phlogopites which are associated with magnetite mineralization prevents the determination of a reliable alteration age. δ18O thermometry reveals a temperature range between 462 and 528 °C for the magnetite mineralization. According to geochemical (trace and rare earth elements), stable (δ18O, δ2H, δ34S, and δ13C), and radiogenic (87Sr/86Sr and 143Nd/144Nd) isotope data, the hydrothermal fluid responsible for the alteration and mineralization is related to the Kesikköprü granitoid, from which a significant magmatic component originates initially, followed by meteoric fluids at lower temperatures (123 °C) during the late-stage formation of calcite–quartz veins. Full article
(This article belongs to the Section Mineral Deposits)
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20 pages, 15795 KB  
Article
Chromogenic Mechanism and Formation of Zonal Genesis of Raspberry-Red Grossular from the Sierra de Cruces Range, Mexico
by Siyuan Wu, Siyi Zhao, Yi Zhao and Chenxi Zhang
Minerals 2025, 15(2), 138; https://doi.org/10.3390/min15020138 - 30 Jan 2025
Viewed by 1280
Abstract
The raspberry-red grossular, discovered in the Sierra de Cruces in Coahuila, Mexico, is characterized by its zoned coloration, featuring a pink rim and a black mantle with a sharp color transition at the border. However, there is a notable lack of definitive and [...] Read more.
The raspberry-red grossular, discovered in the Sierra de Cruces in Coahuila, Mexico, is characterized by its zoned coloration, featuring a pink rim and a black mantle with a sharp color transition at the border. However, there is a notable lack of definitive and systematic identification characteristics pertaining to its special zones. The mineral chemical composition and chromogenic mechanism remain unsupported by empirical validation derived from specific experimental data. In this study, the gemological properties, chemical composition, and spectral characteristics are systematically analyzed to explore the chromogenic mechanism and formation of zonal genesis. The results of the X-ray diffraction pattern, Raman spectrum, and major elements’ composition show that the raspberry-red grossular samples are grossular with high purity. Mn ions are a direct coloring factor of the pink rim of the grossular samples, while Fe ions are chromogenic elements of the black mantle. The MnO content of the pink rim ranges from 0.15 wt% to 1.72 wt%. The FeO content of the black mantle ranges from 3.11 wt% to 5.09 wt%, which is generally higher than that of other parts. The trace element compositions reveal that the rim and core of samples were formed in an oxidative environment (δEu = 0.43–2.41), which could be derived from the hydrothermal metasomatic skarn (δ18O = 11.03–12.14); the mantles of samples were formed in a reducing environment (δEu = 0.42–0.85), which is consistent with the magmatic skarn (δ18O = 11.40–11.66). They also show that the surrounding rocks provide part of the compositional sources for the raspberry-red grossular and interact with the black mantle, which affects the formation of the pink rim. This study offers geological and mineral compositional insights, addressing a significant void in the study of raspberry-red grossular, and lays the foundation for follow-up investigations. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
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16 pages, 22557 KB  
Article
HRTEM Study of Desulfurization of Pt- and Pd-Rich Sulfides from New Caledonia Ophiolite
by Néstor Cano, José M. González-Jiménez, Fernando Gervilla and Thomas N. Kerestedjian
Minerals 2025, 15(1), 66; https://doi.org/10.3390/min15010066 - 12 Jan 2025
Viewed by 2056
Abstract
Oxygen-bearing platinum group minerals (O-bearing PGMs) are intergrown with base metal sulfides (BMS, e.g., pentlandite–[NiFe]9S8) within fractures in chromite grains from chromitite bodies on Ouen Island, New Caledonia. These PGMs are hosted in chlorite and serpentine, which formed during [...] Read more.
Oxygen-bearing platinum group minerals (O-bearing PGMs) are intergrown with base metal sulfides (BMS, e.g., pentlandite–[NiFe]9S8) within fractures in chromite grains from chromitite bodies on Ouen Island, New Caledonia. These PGMs are hosted in chlorite and serpentine, which formed during serpentinization of olivine and pyroxene. The O-bearing PGM grains are polygonal, show microfracturing (indicating volume loss), and contain Pt-Pd-rich sulfide remnants, suggesting pseudomorphic replacement of primary (magmatic) sulfides. They display chemical zonation, with Pt(-Pd-Ni-Fe) relict sulfide cores replaced by Pt-Fe-Ni oxidized alloy mantles and Pt-Cu-Fe(-Pd) alloy rims (tulameenite), indicating desulfurization. The core and mantle show a nanoporous structure, interpreted as the result of coupled dissolution–reprecipitation reactions between magmatic sulfides and low fO2fS2 serpentinite-related fluids, probably formed during olivine transformation to serpentine + magnetite (early stages of serpentinization). This fluid infiltrated magmatic sulfides (PGE-rich and BMS), degrading them to secondary products and releasing S and metals that were accommodated in the mantle and rim of O-bearing PGMs. Upon olivine exhaustion, an increase in fO2 might have stabilized Pt-Fe-O compounds (likely Pt0/Pt-Fe + Fe oxyhydroxides) alongside Ni-Fe alloys. Our results show that post-magmatic desulfurization of primary sulfides produces complex nano-scale intergrowths, mainly driven by changes in the fluid’s physicochemical properties during serpentinization. Full article
(This article belongs to the Section Mineral Geochemistry and Geochronology)
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23 pages, 2497 KB  
Review
Polymethyl Methacrylate Bone Cement Polymerization Induced Thermal Necrosis at the Cement–Bone Interface: A Narrative Review
by Gergo Tamas Szoradi, Andrei Marian Feier, Sandor Gyorgy Zuh, Octav Marius Russu and Tudor Sorin Pop
Appl. Sci. 2024, 14(24), 11651; https://doi.org/10.3390/app142411651 - 13 Dec 2024
Cited by 27 | Viewed by 10357
Abstract
Polymethyl methacrylate (PMMA) bone cement has been a transformative material in orthopedics since its introduction in the mid-20th century. Originally used in dental medicine, PMMA was adopted for orthopedic applications by Sir John Charnley in the 1950s, significantly enhancing joint replacement surgeries. The [...] Read more.
Polymethyl methacrylate (PMMA) bone cement has been a transformative material in orthopedics since its introduction in the mid-20th century. Originally used in dental medicine, PMMA was adopted for orthopedic applications by Sir John Charnley in the 1950s, significantly enhancing joint replacement surgeries. The primary appeal of PMMA lies in its biocompatibility, mechanical strength, and ease of handling, making it a favored choice for various orthopedic procedures, including arthroplasties and limb-salvage surgeries. However, the exothermic polymerization process of PMMA poses a risk of thermal necrosis in the surrounding bone tissue, as local temperatures can exceed 70 °C, causing damage to osteocytes. Research has sought to mitigate these risks by optimizing mixing techniques, reducing cement mantle thickness, and incorporating cooling methods. Recent advancements, such as the use of phase-change materials (PCMs) and alternative monomers, have shown promise in lowering the exothermic peak during polymerization. Other strategies include pre-cooling the cement and prosthetic components and using composite cement. Despite these innovations, managing the balance between minimizing heat generation and maintaining mechanical properties remains a challenge. The impact of thermal necrosis is significant, compromising implant stability and osseointegration. Understanding the complex interactions between PMMA’s thermal properties and its clinical outcomes is essential for improving orthopedic surgical practices and patient recovery. Full article
(This article belongs to the Section Applied Biosciences and Bioengineering)
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