Minerals

22 pages, 18111 KiB

Open AccessArticle

A New Anisotropic Singularity Algorithm to Characterize Geo-Chemical Anomalies in the Duolong Mineral District, Tibet, China

by Jie Tang, Wenlei Wang and Changjiang Yuan

Minerals 2023, 13(7), 988; https://doi.org/10.3390/min13070988 - 24 Jul 2023

Cited by 2 | Viewed by 1446

Abstract

With the increasing exploitation of mineral resources by humans, exploring non-traditional areas for hidden resources such as deep earth and sediment-covered regions has become a significant challenge in the field of mineral exploration. Geochemical data, as a crucial information carrier of geological bodies, [...] Read more.

With the increasing exploitation of mineral resources by humans, exploring non-traditional areas for hidden resources such as deep earth and sediment-covered regions has become a significant challenge in the field of mineral exploration. Geochemical data, as a crucial information carrier of geological bodies, serves as one of the direct and effective sources for quantitative analysis of regional geological evolution and mineralization prediction studies. It plays an indispensable role in geographic information system (GIS)-based mineral exploration. Due to the neglect of spatial distribution characteristics and the variability of statistical features with spatial metrics in traditional statistical methods, this paper employs fractal/multifractal and the local singularity analysis to identify geochemical anomalies from background and characterize geochemical distributions associated with porphyry Cu-Au mineralization in the Duolong mineral district, Tibet, China. A novel algorithm for estimating the singularity index, which takes anisotropy into consideration, is proposed and practically applied to the Duolong district. By comparing with the isotropic singularity index, this new method objectively identifies anisotropic geochemical signatures and investigates non-linear behaviors of ore-forming elements, making it more practical and effective in geo-anomaly extraction. Furthermore, the current method is capable of indicating variations in geochemical distributions at different scales through directional arrows marking analytical windows. The summed-up direction of these multi-scale vectors effectively demonstrates migration trends of ore materials at each location within the study area. The new method can pinpoint the location of ore-forming element accumulation and migration directions, unlocking valuable insights from complex datasets. This promises to revolutionize our understanding of how minerals are formed and distributed within the Earth’s crust. Full article

(This article belongs to the Special Issue Digital Geosciences and Mineral Exploration)

► Show Figures

Figure 1

21 pages, 6516 KiB

Open AccessArticle

Effect of Waste Clay Bricks on the Performance of Cemented Tailings Backfill and Its Damage Constitutive Model

by Tianxiang Sun, Yifan Zhang, Kang Wang, Zhuoqun Yu and Yongyan Wang

Minerals 2023, 13(7), 987; https://doi.org/10.3390/min13070987 - 24 Jul 2023

Viewed by 1011

Abstract

In this study, two types of cemented tailings backfill (CTB) were prepared by breaking up the waste clay bricks (WCB) from dismantled buildings and replacing part of the cement with brick powder and part of the tailings with brick aggregate. The mechanical properties [...] Read more.

In this study, two types of cemented tailings backfill (CTB) were prepared by breaking up the waste clay bricks (WCB) from dismantled buildings and replacing part of the cement with brick powder and part of the tailings with brick aggregate. The mechanical properties of the modified CTB were investigated. The results showed that the strength of CTB with 10% brick powder content increased by 16.24% at the curing age of 28 days, while the content of 20% brick powder only decreased by 0.11%. The strength of the brick aggregate with less than 20% content can be increased at each curing age, and the strength of the 15% brick aggregate at the curing age of 7 d and 28 d is increased by 65.54 and 58.8%. The failure strain of the CTB-containing brick powder decreases with the extension of the curing time, and the failure strain of the CTB-containing brick aggregate decreases significantly at the curing age of 7 days. In addition, a three-stage damage constitutive model was established based on the results obtained in the present study, and the laboratory test results of CTB under uniaxial compression were effectively described with high confidence. Full article

(This article belongs to the Special Issue Cemented Paste Backfill: How Do the Components Affect the Performance?)

► Show Figures

Figure 1

19 pages, 99506 KiB

Open AccessArticle

Integration of Electrical Resistivity Tomography and Induced Polarization for Characterization and Mapping of (Pb-Zn-Ag) Sulfide Deposits

by Mosaad Ali Hussein Ali, Farag M. Mewafy, Wei Qian, Fahad Alshehri, Mohamed S. Ahmed and Hussein A. Saleem

Minerals 2023, 13(7), 986; https://doi.org/10.3390/min13070986 - 24 Jul 2023

Cited by 6 | Viewed by 1929

Abstract

The accurate characterization and mapping of low-grade ore deposits necessitate the utilization of a robust exploration technique. Induced polarization (IP) tomography is a powerful geophysical method for mineral exploration. An integrated survey using electrical resistivity tomography (ERT) and IP was employed in this [...] Read more.

The accurate characterization and mapping of low-grade ore deposits necessitate the utilization of a robust exploration technique. Induced polarization (IP) tomography is a powerful geophysical method for mineral exploration. An integrated survey using electrical resistivity tomography (ERT) and IP was employed in this study to characterize and map (Zn-Pb-Ag) ore deposits in NE New Brunswick, Canada. The survey encompassed twelve parallel lines across the study area. The 2D and 3D inversion of the results provided a detailed image of the resistivity and chargeability ranges of subsurface formations. The boundaries of sulfide mineralization were determined based on resistivity values of (700–2000 Ohm.m) and chargeability values of (3.5 mV/V) and were found to be located at an approximate depth of 80–150 m from the surface. The findings were validated through a comparison with data from borehole logs and mineralogy data analysis. The size and shape of sulfide deposits were successfully characterized and mapped in the study area using this cost-effective mapping approach. Full article

(This article belongs to the Special Issue Pb-Zn Deposits and Associated Critical Metals)

► Show Figures

Figure 1

17 pages, 6412 KiB

Open AccessArticle

Multi-Isotopic Compositions of Ores from the Shizishan Cu–Au–Mo Orefield in the Tongling Region, Eastern China: Implications for Ore Genesis

by Jinwei Li, Lichuan Pan, Yitong Guo and Shunfu Lu

Minerals 2023, 13(7), 985; https://doi.org/10.3390/min13070985 - 24 Jul 2023

Viewed by 925

Abstract

The Middle–Lower Yangtze Metallogenic Belt (MLYMB) hosts abundant porphyry–skarn–stratabound-type Cu–Au–Mo deposits. Despite extensive research, the origin of the stratabound-type deposits, which developed at the unconformity interface between the Devonian and Carboniferous strata in the MLYMB, remains controversial. The primary debate centers on whether [...] Read more.

The Middle–Lower Yangtze Metallogenic Belt (MLYMB) hosts abundant porphyry–skarn–stratabound-type Cu–Au–Mo deposits. Despite extensive research, the origin of the stratabound-type deposits, which developed at the unconformity interface between the Devonian and Carboniferous strata in the MLYMB, remains controversial. The primary debate centers on whether these deposits are the result of Carboniferous sedimentary exhalative mineralization or Mesozoic magmatic–hydrothermal mineralization. In this paper, we examine three representative deposits in the Shizishan orefield: the Chaoshan skarn-type Au deposit, the Hucun porphyry–skarn-type Cu–Mo deposit, and the Dongguashan Cu–(Au) deposit, which has a disputed genesis of its stratiform orebodies. Economically important ore minerals, such as chalcopyrite, molybdenite, and pyrrhotite, and their associated quartz and calcite, were focused on, rather than the extensively studied pyrite in the Tongling region. The ore genesis and sources of mineralized elements in the Shizishan orefield were investigated using H, O, C, S, Pb, and Cu isotopes. The H–O isotopic compositions of hydrothermal quartz from the Chaoshan, Dongguashan, and Hucun deposits indicate that the ore-forming fluids were mainly magmatic water with some meteoric water input. The C–O isotopic compositions of calcite show a large difference from the local sedimentary carbonates. The S isotopic compositions of sulfides reveal a magmatic sulfur signature. The Pb isotopic compositions in the three deposits are similar to those of the Shizishan intrusions, suggesting a magmatic source for Pb. The Cu isotopic compositions of chalcopyrite and pyrrhotite demonstrate that Cu, the primary ore-forming element, was mainly derived from magmatic–hydrothermal fluids. The stratiform orebodies display H–O–C–S–Pb–Cu isotopes consistent with the porphyry orebodies in the Dongguashan deposit, as well as in the Chaoshan and Hucun deposits, indicating a common ore genesis. From these, we conclude that the porphyry–skarn–stratabound-type Cu–Au–Mo deposits in the Shizishan orefield can be classified as a unified Mesozoic magmatic–hydrothermal metallogenic system. The stratabound-type copper sulfide deposits and the porphyry–skarn-type copper deposits in the MLYMB have a strong similarity in the source and genesis of their ore-forming elements. Full article

(This article belongs to the Section Mineral Deposits)

► Show Figures

Figure 1

21 pages, 5585 KiB

Open AccessArticle

Three-Dimensional Geological–Geophysical Modeling and Prospecting Indications of the Ashele Ore Concentration Area in Xinjiang Based on Irregular Sections

by Guang Qi, Guixiang Meng, Jiayong Yan, Hejun Tang and Ronghui Xue

Minerals 2023, 13(7), 984; https://doi.org/10.3390/min13070984 - 24 Jul 2023

Cited by 1 | Viewed by 936

Abstract

The Ashele ore concentration area is an important area for polymetallic ore concentration in Xinjiang, China. Scholars have made progress in understanding the ore-controlling structures, ore-bearing horizons, and metallogenic age of this area. However, there are still uncertainties about the 3D distributions of [...] Read more.

The Ashele ore concentration area is an important area for polymetallic ore concentration in Xinjiang, China. Scholars have made progress in understanding the ore-controlling structures, ore-bearing horizons, and metallogenic age of this area. However, there are still uncertainties about the 3D distributions of plutons, fault structures, and ore-bearing strata, which restrict the development of deep and peripheral ore prospecting and the discovery of new ore bodies in the area. This study proposes a geological–geophysical modeling method based on irregular sections and uses this method to establish a 3D geological–geophysical model based on physical property data, boreholes, surface geological maps, and geophysical data. The model shows that the study area has many hidden rock masses with various depths and shapes and fracture structures with complex shapes. The fault structure in the area is complex, and the ore bodies are controlled by the faults. The ore-bearing geological units (Ashele Formation) exhibit an obvious east–west-trending W-shaped fold structure. The deep part of the northern Ashele Formation extends northward slightly, and the southern Ashele Formation has thick strata, with depths generally greater than 2 km. Based on the information on deep structures provided by the model, three metallogenic prospective areas are predicted, which points out the direction for further prospecting work in the ore concentration area and shows that the adopted modeling method and process have good applicability for constructing 3D models of ore concentration areas with sparse data, large area, and complex geological structures. The proposed modeling method provides technical support for ore prospecting, particularly in the overburden area or ore concentration area with sparse data. Full article

(This article belongs to the Special Issue Recent Advances in Deep Ore Prospecting)

► Show Figures

Figure 1

13 pages, 9303 KiB

Open AccessArticle

Influence of Key Strata on the Evolution Law of Mining-Induced Stress in the Working Face under Deep and Large-Scale Mining

by Jianlin Xie, Shan Ning, Weibing Zhu, Xiaozhen Wang and Tao Hou

Minerals 2023, 13(7), 983; https://doi.org/10.3390/min13070983 - 24 Jul 2023

Cited by 3 | Viewed by 806

Abstract

When there are multiple key strata in the overburden of a deep coal seam and the surface subsidence coefficient after mining is small, this indicates that the overlying key strata fail to break completely after mining. On this occasion, stress is easily concentrated [...] Read more.

When there are multiple key strata in the overburden of a deep coal seam and the surface subsidence coefficient after mining is small, this indicates that the overlying key strata fail to break completely after mining. On this occasion, stress is easily concentrated in the working face, which in turn leads to the occurrence of dynamic disasters such as rock bursts. This study adopted a comprehensive analysis method of field monitoring and numerical simulations to explore the influence of the key stratum on the evolution law of mining-induced stress in the working face. A distributed optical fiber sensor (DOFS) and a surface subsidence GNSS monitoring system were arranged inside and at the mouth of the ground observation borehole, respectively. According to the monitoring results of strain obtained from the DOFS, the height of the broken stratum inside the overlying strata was obtained and according to the monitoring results of surface subsidence, the surface subsidence coefficient was proven to be less than 0.1, indicating that the high key stratum is not broken completely, but enters a state of bending subsidence instead. In order to reveal the influence of the key stratum on the mining-induced stress of the working face, two 3DEC numerical models with and without the key stratum were established for a comparative analysis. As the numerical simulation results show, when there are multiple key strata in the overburden, the stress influence range and the stress concentration coefficient of the coal seam after mining are relatively large. The study revealed the working mechanism of rock burst accidents after large-scale mining and predicted the potential area with a rock burst risk after mining of the working face, which was verified by field investigations. The research results are of great guiding significance for the identification of the working mechanism of rock bursts in deep mining condition and for their prevention and control. Full article

► Show Figures

Figure 1

29 pages, 13074 KiB

Open AccessArticle

Addressing Geological Challenges in Mineral Resource Estimation: A Comparative Study of Deep Learning and Traditional Techniques

by Nurassyl Battalgazy, Rick Valenta, Paul Gow, Carlos Spier and Gordon Forbes

Minerals 2023, 13(7), 982; https://doi.org/10.3390/min13070982 - 24 Jul 2023

Viewed by 2333

Abstract

Spatial prediction of orebody characteristics can often be challenging given the commonly complex geological structure of mineral deposits. For example, a high nugget effect can strongly impact variogram modelling. Geological complexity can be caused by the presence of structural geological discontinuities combined with [...] Read more.

Spatial prediction of orebody characteristics can often be challenging given the commonly complex geological structure of mineral deposits. For example, a high nugget effect can strongly impact variogram modelling. Geological complexity can be caused by the presence of structural geological discontinuities combined with numerous lithotypes, which may lead to underperformance of grade estimation with traditional kriging. Deep learning algorithms can be a practical alternative in addressing these issues since, in the neural network, calculation of experimental variograms is not necessary and nonlinearity can be captured globally by learning the underlying interrelationships present in the dataset. Five different methods are used to estimate an unsampled 2D dataset. The methods include the machine learning techniques Support Vector Regression (SVR) and Multi-Layer Perceptron (MLP) neural network; the conventional geostatistical methods Simple Kriging (SK) and Nearest Neighbourhood (NN); and a deep learning technique, Convolutional Neural Network (CNN). A comparison of geologic features such as discontinuities, faults, and domain boundaries present in the results from the different methods shows that the CNN technique leads in terms of capturing the inherent geological characteristics of given data and possesses high potential to outperform other techniques for various datasets. The CNN model learns from training images and captures important features of each training image based on thousands of calculations and analyses and has good ability to define the borders of domains and to construct its discontinuities. Full article

(This article belongs to the Special Issue Geostatistics in the Life Cycle of Mines)

► Show Figures

Figure 1

26 pages, 25286 KiB

Open AccessArticle

Characteristics of Seismogenic Dust Particles from a Mountain and Their Significance for Paleoseismic Records in a Tufa Section: A Case Study of Jiuzhaigou, China

by Shengwen Jing, Fudong Wang, Enrico Capezzuoli, Guoqing Huang, Junhao Li, Hanchao Jiang, Zijian Zhou, Xueqin Zhao, Faqin Dong and Andrea Brogi

Minerals 2023, 13(7), 981; https://doi.org/10.3390/min13070981 - 24 Jul 2023

Cited by 1 | Viewed by 1100

Abstract

The sedimentary characteristics of the special interlayer contained in the section of the Sparkling Lake dam revealed by the 8 August Jiuzhaigou earthquake in 2017 are obviously different from the tufa in the dam body, and they are considered to be historic flood [...] Read more.

The sedimentary characteristics of the special interlayer contained in the section of the Sparkling Lake dam revealed by the 8 August Jiuzhaigou earthquake in 2017 are obviously different from the tufa in the dam body, and they are considered to be historic flood relics. Based on the study of the particulate matter from the 8 August Jiuzhaigou earthquake, this study combined comparative petrographic, mineralogical, geochemical, and chronological studies of the special interbedded sediments of the Sparkling Lake dam with other genetic samples to obtain homology information and genetic links and to explore the tufa depositional dynamics and earthquake disaster subsidence. The paleoseismic benefit in the discontinuity layer was explored, and the paleoseismic information embedded in the profiles was extracted, providing a new idea for reconstructing the paleoseismic events in the tufa deposition sequence. According to X-ray diffraction, laser particle size analysis, and scanning electron microscope experiments, the particulate matter in the Jiuzhaigou mountains has its own specific mineralogical characteristics. The mineral composition of the particulate matter is basically calcite. The particle size is large, and single particles are mostly angular and subangular. The fracture morphology observed under the single-particle microscope was uneven, showing the characteristics of the dust caused by earthquake disasters. The geochemical analysis data show that the distribution patterns of rare earth elements in different types of particulate matter in the same area have similar characteristics. Moreover, an analysis of the elements Rb, Sr, and Ba shows that the particulate matter in Jiuzhaigou has a strong correlation (R² = 0.9941), indicating the stability and uniformity of the material source. The source of the particulate matter was limestone of the carbonate strata from the Devonian to the Triassic. Combined with mineralogy and grain size morphology, the interbedded particles in the tufa depositional profile have the potential application of paleoseismic archives to record extreme seismic events. According to the chronological data of the special interlayer sediments in the tufa dam body, the paleoseismic age is inferred to be 1220 ± 30 BP. Therefore, the tufa bedding can be related to the paleoearthquake, and the special interlayer of the tufa section can be used to reconstruct paleoearthquakes. Full article

(This article belongs to the Special Issue Global and Regional Tectonics: Insights from Sedimentary Records and Geochemistry)

► Show Figures

Figure 1

18 pages, 3006 KiB

Open AccessFeature PaperArticle

Antiperthite and Mesoperthite Exsolution Textures in the Zhengjiapo BIF, Changyi Metallogenic Belt, North China Craton: Evidence of UHT Metamorphic Overprint

by Yan-Rong Chen, Xu-Ping Li, Zeng-Sheng Li, Hans-Peter Schertl and Fan-Mei Kong

Minerals 2023, 13(7), 980; https://doi.org/10.3390/min13070980 - 24 Jul 2023

Cited by 1 | Viewed by 1066

Abstract

Paleoproterozoic banded iron formation (BIF) iron ore of the Zhengjiapo region of the Changyi metallogenic belt, Eastern Block of North China Craton contains abundant coexisting antiperthite and mesoperthite textures. The antiperthite and mesoperthite occur in felsic domains of the Zhengjiapo BIF ore and [...] Read more.

Paleoproterozoic banded iron formation (BIF) iron ore of the Zhengjiapo region of the Changyi metallogenic belt, Eastern Block of North China Craton contains abundant coexisting antiperthite and mesoperthite textures. The antiperthite and mesoperthite occur in felsic domains of the Zhengjiapo BIF ore and enable derivation of peak temperature metamorphic conditions. Thermodynamic phase modeling shows that equilibrium conditions of corresponding textures, considering the related mineral assemblage of Pl + Qz + Kfs + Mag + Opx + L, are in the range of 870–940 °C and 5.0–6.8 kbar. Ternary feldspar thermometry using reintegrated compositions of antiperthite and mesoperthite in the felsic domain of the studied BIF iron ore reveals even higher peak metamorphic temperatures of 1045–1080 °C. The ultra-high temperature–low pressure conditions of Precambrian BIF have not yet been reported from the North China Craton. The documented ultra-high temperature metamorphism of the Zhengjiapo BIF iron ore in the Changyi metallogenic belt indicates that the BIF was involved in the collision-related tectonic process during Paleoproterozoic to have occurred in the Jiao-Liao-Ji orogenic belt. Full article

(This article belongs to the Section Mineral Geochemistry and Geochronology)

► Show Figures

Graphical abstract

13 pages, 5735 KiB

Open AccessArticle

Conversion of Activated Calcium in Industrial Water to Micron CaCO₃ Powder Based on CO₂ Absorption and Mineralization

by Xiao-Long Li, Yan Liu and Ting-An Zhang

Minerals 2023, 13(7), 979; https://doi.org/10.3390/min13070979 - 23 Jul 2023

Viewed by 1357

Abstract

Carbon dioxide capture, utilization, and storage (CCUS) is one of the essential approaches to achieving permanent CO₂ emission reduction. A new idea of absorbing and mineralizing CO₂ with industrial wastewater and converting activated calcium into micron CaCO₃ powder is proposed [...] Read more.

Carbon dioxide capture, utilization, and storage (CCUS) is one of the essential approaches to achieving permanent CO₂ emission reduction. A new idea of absorbing and mineralizing CO₂ with industrial wastewater and converting activated calcium into micron CaCO₃ powder is proposed in this paper, which synchronizes water softening and CO₂ fixation. Therefore, this paper investigated the characteristics of circulating water quality in the iron and steel industry and the transformation behaviors of CO₂ capture by activated calcium to CaCO₃ powder in the mild aqueous environment under different process parameters. The phase composition, morphology, and particle size distribution (PSD) of CaCO₃ powder were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and (laser particle size analyzer) LPSA, respectively. In addition, a green integrated cycle system for industrial water capture of mineralized CO₂ was preliminarily constructed, which provides a reference method for carbon reduction and economic utilization of carbon sources in an industrial system. Full article

(This article belongs to the Special Issue Comprehensive Utilization of Metallurgical Slag)

► Show Figures

Figure 1

17 pages, 8739 KiB

Open AccessArticle

Application of Analytic Hierarchy Process in Mineral Prospecting Prediction Based on an Integrated Geology-Aerogeophysics-Geochemistry Model

by Yongzai Xi, Yongbo Li, Junjie Liu, Shan Wu, Ning Lu, Guixiang Liao and Qiule Wang

Minerals 2023, 13(7), 978; https://doi.org/10.3390/min13070978 - 23 Jul 2023

Cited by 3 | Viewed by 952

Abstract

Determining mineral prospecting targets is crucial for mineral prediction and evaluation. In this study, an evaluation index system for solid mineral exploration and metallogenic target assessment was established using the Analytic Hierarchy Process (AHP) for the Naoniushan area (China). Furthermore, an integrated model [...] Read more.

Determining mineral prospecting targets is crucial for mineral prediction and evaluation. In this study, an evaluation index system for solid mineral exploration and metallogenic target assessment was established using the Analytic Hierarchy Process (AHP) for the Naoniushan area (China). Furthermore, an integrated model combining geology–aerogeophysics–geochemistry was developed for copper, lead, zinc, silver, and other polymetallic deposits. The information content of each index in the model was reasonably assigned, and the mineral prospecting targets in the central and southern parts of the Daxinganling were recommended. By focusing on the copper polymetallic mineral prospecting target in the Naoniushan area, this paper demonstrates that the AHP method can comprehensively consider various influencing factors and their interactions, realize a reasonable division of the optimal mineral prospecting target, and reflect the key factors affecting the mineral prospecting target to a certain extent. Importantly, this approach reduces the influence of human subjective factors, and the optimization results are objective and scientifically grounded. Full article

(This article belongs to the Section Mineral Exploration Methods and Applications)

► Show Figures

Figure 1

37 pages, 32461 KiB

Open AccessArticle

Timurid, Ottoman, Safavid and Qajar Ceramics: Raman and Composition Classification of the Different Types of Glaze and Pigments

by Philippe Colomban and Gulsu Simsek Franci

Minerals 2023, 13(7), 977; https://doi.org/10.3390/min13070977 - 23 Jul 2023

Cited by 1 | Viewed by 1500

Abstract

Raw materials significantly determine the final composition and properties of a fired ceramic. Raman analysis which characterizes micro- and nanostructures of (coloured) glazes, opacified or not, was applied to shards mostly collected before the 1960s, currently at the Louvre Museum, originated in Anatolia, [...] Read more.

Raw materials significantly determine the final composition and properties of a fired ceramic. Raman analysis which characterizes micro- and nanostructures of (coloured) glazes, opacified or not, was applied to shards mostly collected before the 1960s, currently at the Louvre Museum, originated in Anatolia, the Caucasus, Iran and Central Asia, which are, for most of them, characterized by the use of black lines to separate coloured areas, and dated to the period between the 12th and 19th centuries. Measurements were carried out in the laboratory with a blue laser excitation and/or on the conservation site with a mobile device (green laser). Three types of glazes were identified by their nanostructure of the silicate network: (i) a lead-rich glaze analogous to that of Byzantine, Zirid to Hafsid and al-Andalus productions, (ii) a lead-alkali glaze typical of the Ottoman productions of Iznik-Kütahya, and (iii) a mixed (poor lead/lead-free)-alkali glaze typical of Safavid productions. The colour determines the precise composition of the glaze. The identification is not only based on the signature of the stretching mode of the SiO₄ tetrahedron (position of the wavenumber of the component(s)) but also on the position and shape of the continuous luminescence of the Raman background, characteristic of the raw materials used. Lead-tin yellow, Fe-rich, Mn-rich and Cr-rich black pigments and opacifiers made of cassiterite and wollastonite were also identified. The results (type of glaze and deduced processing temperature) were discussed in the light of the ternary phase diagrams visualizing elemental composition determined in previous works and the microstructure examination on the polished section (defining single or multistep firing cycles). Continuity was highlighted on the one hand between the tiles of Bursa, Edirne and Istanbul (Ottoman Iznik-like production) and on the other hand between those of Samarkand area (Timurid) and Iran. The procedure was then applied in the study of three objects (two dishes and a bowl) which are very representative of the productions of the Turkish-Persian cultural areas: a polychrome mina’i cup with decoration representing a rider, an Ottoman Iznik fritware with polychrome floral decoration, and a blue-and-white Safavid ceramic with a decoration representing a shrub. Full article

(This article belongs to the Special Issue Vibrational Spectroscopy in Mineralogy and Archaeology)

► Show Figures

Figure 1

19 pages, 18549 KiB

Open AccessFeature PaperArticle

Characterizing Microbial and CO₂-Induced Carbonate Minerals: Implications for Soil Stabilization in Sandy Environments

by Hamed Abdeh Keykha, Alireza Zangani, Hadi Mohamadzadeh Romiani, Afshin Asadi, Satoru Kawasaki and Niloofar Radmanesh

Minerals 2023, 13(7), 976; https://doi.org/10.3390/min13070976 - 23 Jul 2023

Viewed by 1206

Abstract

This study aimed to investigate the structure and shape of carbonate crystals induced through microbial activity and carbon dioxide reactions in the sand. The strength of sandy soil treated with carbonate minerals was subsequently determined using unconfined compression strength (UCS) tests. Sporoscarcina pasteurii [...] Read more.

This study aimed to investigate the structure and shape of carbonate crystals induced through microbial activity and carbon dioxide reactions in the sand. The strength of sandy soil treated with carbonate minerals was subsequently determined using unconfined compression strength (UCS) tests. Sporoscarcina pasteurii bacteria were used to produce an aqueous solution of free carbonate ions (CO₃²⁻) under laboratory circumstances called microbial-induced carbonate precipitation (MICP). In CO₂-induced carbonate precipitation (CICP), carbon dioxide was added to a sodium hydroxide solution to form free carbonate ions (CO₃²⁻). Different carbonate mineral compositions were then provided by adding Fe²⁺, Mg²⁺, and Ca²⁺ ions to carbonate ions (CO₃²⁻). In the MICP and CICP procedures, the results of scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) revealed a distinct morphology of any type of carbonate minerals. Vaterite (CaCO₃), siderite (FeCO₃), nesquehonite (MgCO₃(H₂O)₃), and dolomite (CaMg(CO₃)₂ were produced in MICP. Calcite (CaCO₃), siderite (FeCO₃), nesquehonite (MgCO₃(H₂O)₃), and high-Mg calcite (Ca-Mg(CO₃)) were produced in CICP. According to UCS data, siderite and high-Mg calcite/dolomite had more effectiveness in increasing soil strength (63–72 kPa). The soils treated with nesquehonite had the lowest strength value (25–29 kPa). Mineral-treated soils in CICP showed a slightly higher UCS strength than MICP, which could be attributable to greater particle size and interlocking. This research focused on studying the mineralogical properties of precipitated carbonate minerals by CICP and MICP methods to suggest a promising environmental method for soil reinforcement. Full article

(This article belongs to the Section Biomineralization and Biominerals)

► Show Figures

Figure 1

26 pages, 9733 KiB

Open AccessArticle

Late Triassic Tectonic Setting in Northeastern Margin of North China Craton: Insight into Sedimentary and Apatite Fission Tracks

by Shuang Tang, Shichao Li, Xinmei Zhang, Daixin Zhang, Hongtao Wang, Lijun Nie, Xiaodong Zhou and Mengqi Li

Minerals 2023, 13(7), 975; https://doi.org/10.3390/min13070975 - 22 Jul 2023

Viewed by 1026

Abstract

The closure timing of the Paleo-Asian Ocean and the terminal stage of the Central Asian Orogenic Belt have been widely debated in the geological community. It’s known that the gradual scissor-like closure of the Paleo-Asian Ocean occurred from west to east during the [...] Read more.

The closure timing of the Paleo-Asian Ocean and the terminal stage of the Central Asian Orogenic Belt have been widely debated in the geological community. It’s known that the gradual scissor-like closure of the Paleo-Asian Ocean occurred from west to east during the Paleozoic period. However, it was not until the Triassic period that the complete closure of the ocean occurred at the northeastern margin of the North China Craton. Nevertheless, there is still much uncertainty regarding the Late Triassic tectonic setting in Northeast China. In this study, we focused on the Upper Triassic Dajianggang Formation, located in the Shuangyang area of central Jilin Province, which is situated on the northeastern margin of the North China Plate. Our aim was to determine the formation age of the Dajianggang Formation by analyzing the detrital particle composition, petrogeochemistry, detrital zircon U-Pb isotope dating, and apatite fission track thermochronology. Our results indicated that the primary sandstone provenance area of the Dajianggang Formation in the Shuangyang area is the island arc orogenic belt. The tectonic background of the sandstone provenance area is mainly a continental island arc environment. The provenance area is mostly composed of felsic rocks with sedimentary tendencies, and some of its material may have originated from the northern margin of the North China Craton or the eroded recycle orogenic belt. LA-ICP-MS U-Pb dating of detrital zircons shows that the Dajianggang Formation formed after 226.8 ± 5 Ma. Moreover, analysis of the thermal evolution history modelling shows that the Dajianggang Formation in the Shuangyang area continued to be deposited and heated in the early stage, and then experienced rapid exhumation around 30 Ma. This suggests that the study area underwent an orogenic process during the early stage of formation, but then transitioned into a post-orogenic extension period, which constrained the final closure of the Paleo-Asian Ocean prior to the Late Triassic period. In addition, our study indicates that the remote effect of the Pacific subduction did not reach the study area until 30 Ma. The central age of the detrital apatite fission track of sample 19DJ-1 is 94.2 ± 8.3 Ma, which is younger than its corresponding stratigraphic age. The two peak ages of the fission track analysis are 62.9 ± 5.4 Ma and 126 ± 11 Ma. These findings provide new evidence for the tectonic evolution of Northeast China and shed light on the Late Triassic tectonic setting, as well as the influence time of subsequent tectonic domains in the southern part of Northeast China. Full article

(This article belongs to the Special Issue Tectonic–Magmatic Evolution and Mineralization Effect in the Southern Central Asian Orogenic Belt)

► Show Figures

Figure 1

17 pages, 32248 KiB

Open AccessArticle

Material Characterization of Mayapán’s Effigy Censers’ Sherds

by Miguel Pérez, Oscar G. de Lucio, Alejandro Mitrani, Carlos Peraza Lope, Wilberth Cruz Alvarado and Soledad Ortiz Ruiz

Minerals 2023, 13(7), 974; https://doi.org/10.3390/min13070974 - 22 Jul 2023

Viewed by 1014

Abstract

Ceramic production from ancient Mesoamerican civilizations is related with cultural and technological evolution processes. Studying ritual objects also provides information on ancient traditions and allows researchers to determine the importance of certain materials employed in its manufacture. In this work, a set of [...] Read more.

Ceramic production from ancient Mesoamerican civilizations is related with cultural and technological evolution processes. Studying ritual objects also provides information on ancient traditions and allows researchers to determine the importance of certain materials employed in its manufacture. In this work, a set of 72 of Mayapán’s effigy censers’ sherds was analyzed in situ by using a combination of non-invasive, non-destructive spectroscopic and imaging techniques for material characterization; colorimetry established an initial classification of the pigments present in the objects, XRF provided elemental information, FORS allowed us to describe the molecular characteristics, and hyperspectral imaging established compositional contrasts or similitudes between large regions of the different objects. Pigments were characterized, allowing us to describe the materials used in the decorations of such ritual objects. The pottery matrix was also characterized, leading to a detailed description of the clays and mixtures of minerals employed in the construction of the effigy censers. Full article

(This article belongs to the Special Issue Characterization and Provenance of Archaeological Materials Using Multi-Method Analysis)

► Show Figures

Figure 1

13 pages, 5689 KiB

Open AccessArticle

Distribution of Radionuclides in the Surface Covering of the Barun Uranium Mining Area in Erlian Basin, Inner Mongolia

by Cong Yu, Binlin Jia, Liancheng Shi, Mengke Han and Nanping Wang

Minerals 2023, 13(7), 973; https://doi.org/10.3390/min13070973 - 22 Jul 2023

Viewed by 886

Abstract

In order to identify the distribution pattern of radionuclides in the surface soil in the area of a sandstone-type uranium deposit, and to explore its spatial relationship with the location of the orebody, soil radon measurements and ground gamma-ray spectroscopy were carried out [...] Read more.

In order to identify the distribution pattern of radionuclides in the surface soil in the area of a sandstone-type uranium deposit, and to explore its spatial relationship with the location of the orebody, soil radon measurements and ground gamma-ray spectroscopy were carried out in the Barun study area, and soil properties were analyzed. The results show that the soil radon concentrations exhibited a bimodal feature, while the uranium content showed a decreasing trend along the tendency direction of the orebody. In the ground projection area of the orebody, radon concentration showed a positive correlation with uranium content, with both showing relatively low values. Combined with the results of field geological observation and soil property analysis, it is believed that the relatively low radon concentration and uranium content above the orebody is related to the soil being mainly sandy soil. Relatively high uranium values are distributed within approximately 1.5 km north of the northern boundary of the orebody and near the southern boundary of the orebody. High-value radon anomalies occur within about 2 km north of the northern boundary of the orebody and within about 1.3 km south of the southern boundary of the orebody. Full article

(This article belongs to the Section Mineral Exploration Methods and Applications)

► Show Figures

Figure 1

19 pages, 6496 KiB

Open AccessArticle

Low-Dimensional Multi-Trace Impedance Inversion in Sparse Space with Elastic Half Norm Constraint

by Nanying Lan, Fanchang Zhang, Kaipan Xiao, Heng Zhang and Yuhan Lin

Minerals 2023, 13(7), 972; https://doi.org/10.3390/min13070972 - 22 Jul 2023

Cited by 1 | Viewed by 847

Abstract

Recently, multi-trace impedance inversion has attracted great interest in seismic exploration because it improves the horizontal continuity and fidelity of the inversion results by exploiting the lateral structure information of the strata. However, computational inefficiency affects its practical application. Furthermore, in terms of [...] Read more.

Recently, multi-trace impedance inversion has attracted great interest in seismic exploration because it improves the horizontal continuity and fidelity of the inversion results by exploiting the lateral structure information of the strata. However, computational inefficiency affects its practical application. Furthermore, in terms of vertical constraints on the model parameters, it only considers smooth features while ignoring sharp discontinuity features. This leads to yielding an over-smooth solution that does not accurately reflect the distribution of underground rock. To deal with the above situations, we first develop a low-dimensional multi-trace impedance inversion (LMII) framework. Inspired by compressed sensing, this framework utilizes low-dimensional measurements in sparse space containing the maximum information of the signal to construct the objective function for multi-trace inversion, which can significantly reduce the size of the inversion problem and improve the inverse efficiency. Then, we introduce the elastic half (EH) norm as a vertical constraint on the model parameters in the LMII framework and formulate a novel constrained LMII model for impedance inversion. Because the introduced EH norm takes into account both the smoothness and blockiness of rock impedance, the constrained LMII model can effectively raise the inversion accuracy of complex strata. Finally, an efficient alternating multiplier iteration algorithm is derived based on the variable splitting technique to optimize the constrained LMII model. The performance of the developed approaches is tested using synthetic and practical data, and the results prove their feasibility and superiority. Full article

(This article belongs to the Special Issue Application of Geophysical Data Interpretation in Geological and Mineral Potential Mapping)

► Show Figures

Figure 1

21 pages, 51815 KiB

Open AccessArticle

The Earliest Clastic Sediments of the Xiong’er Group: Implications for the Early Mesoproterozoic Sediment Source System of the Southern North China Craton

by Yuan Zhang, Guocheng Zhang and Fengyu Sun

Minerals 2023, 13(7), 971; https://doi.org/10.3390/min13070971 - 22 Jul 2023

Viewed by 892

Abstract

The volcanic activity of the Xiong’er Group and its concomitant sedimentation are related to the stretching–breakup of the Columbia supercontinent. The Dagushi Formation overlies the Paleoproterozoic Shuangfang Formation with an angular unconformity. The Dagushi Formation, as the earliest clastic strata of the Xiong’er [...] Read more.

The volcanic activity of the Xiong’er Group and its concomitant sedimentation are related to the stretching–breakup of the Columbia supercontinent. The Dagushi Formation overlies the Paleoproterozoic Shuangfang Formation with an angular unconformity. The Dagushi Formation, as the earliest clastic strata of the Xiong’er Group and the first stable sedimentary cover overlying the Archean crystalline basement in the southern margin of the North China Craton, provides tectonic evolution information that predates Xiong’er volcanic activity. By distinguishing lithologic characteristics and sedimentary structures, we identified that the sedimentary facies of the Dagushi Formation were braided river delta lake facies from bottom to top. The U–Pb ages of the detrital zircons of the Dagushi Formation can be divided into four groups: ~1905–1925, ~2154–2295, ~2529–2536, and ~2713–2720 Ma, indicating the provenance from the North China Craton basement. Based on the geochemical characteristics of the Dagushi Formation, we suggest that the sediments accumulated rapidly near the source, which were principally felsic in nature, and were supplemented by recycled materials. The provenance area pointed to the underlying metamorphic crystalline basement of the North China Craton as the main source area with an active tectonic background. The Chemical Index of Alteration (CIA) values of the Dagushi Formation sandstone samples ranged from 60.8 to 76.7, indicating that the source rocks suffered from slight to moderate chemic chemical weathering. The Index of Composition Variability (ICV) values ranged from 0.8 to 1.3, which indicates the first cyclic sediments. The vertical facies and provenance changes of the Dagushi Formation reflect a continuous crust fracturing process that occurred in the North China Craton. Full article

(This article belongs to the Special Issue Formation and Evolution of the Continental Crust in North China Craton during Precambrian)

► Show Figures

Figure 1

14 pages, 4639 KiB

Open AccessArticle

Apatite–Calcite Flotation Separation Using Sodium N-Lauroylsarcosinate as a Selective Collector

by Mohamed M. Abdel-Halim, Ruihua Fan, Mohamed A. Abdel Khalek, Renji Zheng, Shihong Xu and Zhiyong Gao

Minerals 2023, 13(7), 970; https://doi.org/10.3390/min13070970 - 21 Jul 2023

Viewed by 1160

Abstract

Froth flotation is a commonly utilized beneficiation technique for effectively separating apatite from other gangue minerals, such as calcite. It is difficult to achieve good separation with fatty acid collectors due to their similar interactions with apatite and calcite. In this work, sodium [...] Read more.

Froth flotation is a commonly utilized beneficiation technique for effectively separating apatite from other gangue minerals, such as calcite. It is difficult to achieve good separation with fatty acid collectors due to their similar interactions with apatite and calcite. In this work, sodium N-lauroyl sarcosinate (SNLS) was used as the collector for the selective separation of calcite from apatite without a depressant. The experiments revealed that SNLS had a much better selectivity and a stronger affinity with calcite compared to apatite, with little effect on the flotation of apatite observed at a pH of 10. Fourier transform infrared (FTIR) analyses were conducted to explain the selective collector process of SNLS. The mechanism experiments demonstrate that SNLS can chemically bond to apatite and calcite minerals to produce Ca-NLS chelates. The active O atoms of the amide and carboxyl groups of SNLS accomplish this. Calcite has a greater Ca-reactivity than apatite, and as a result, the adsorption quantity on the calcite surface is greater than that on the apatite surface. FTIR analyses indicate that SNLS exhibits a greater affinity for the calcite surface than for apatite, a finding that is supported by first-principle density functional theory (DFT) calculations showing a higher adsorption energy of SNLS on the calcite surface. DFT calculations showed that SNLS forms stronger O-Ca bonds on the calcite surface and is less hindered by H₂O. This work shows that the surfactant sodium N-lauroylsarcosinate (SNLS) can be an ideal collector for the flotation of phosphate minerals. Full article

(This article belongs to the Special Issue Recent Advances in Flotation Process)

► Show Figures

Figure 1

17 pages, 3427 KiB

Open AccessArticle

Mode of Occurrence and Distribution of Critical Metal Lithium and Other Trace Elements during Coal Preparation from Jiashun High-Sulfur Coal in Guizhou Province, China

by Yuxuan Zhu, Piaopiao Duan, Wenfeng Wang and Aleksei Kholodov

Minerals 2023, 13(7), 969; https://doi.org/10.3390/min13070969 - 21 Jul 2023

Viewed by 942

Abstract

During the Late Permian period, the coal from the Jiashun Mine in Xingren City, Guizhou Province, China, is characterized by a high sulfur (5.84%) and lithium (Li) (94.5 μg/g) content. Lithium is a critical metal in the context of global energy transition. Considering [...] Read more.

During the Late Permian period, the coal from the Jiashun Mine in Xingren City, Guizhou Province, China, is characterized by a high sulfur (5.84%) and lithium (Li) (94.5 μg/g) content. Lithium is a critical metal in the context of global energy transition. Considering the importance of environmental protection and resource utilization, the mode of occurrence and distribution of trace elements in different coal preparation products were investigated. The obtained results indicated the following: (1) The minerals in Jiashun coal were mainly composed of veined and epigenetic pyrite, quartz, and kaolinite. Most of the minerals could be effectively removed from the cleaned coal through gravity separation. (2) The mode of occurrence of rare earth elements and yttrium (REY) in the coal was relatively complex, and they were mainly found in middlings from gravity separation and in flotation tailings. (3) The mode of occurrence of the trace elements in the coal significantly influenced their removal rate. The removal rate was significantly higher for trace elements removed through gravity separation compared to those removed using flotation. The trace elements mainly found in fine-grained minerals wrapped by organic matter or combined with organic portions had better removal results through flotation. The trace elements that occurred both in the minerals and organic matters had low removal rates (<25%) using two coal preparation methods. (4) Li was more enriched in the middlings from gravity separation (98 μg/g) and in flotation tailings (102 μg/g), reaching the marginal grade (80 μg/g) of Li in coal. (5) Li in Jiashun coal may be derived from intermediate-felsic rocks at the top of the Kangdian Upland and late hydrothermal solutions. Full article

(This article belongs to the Special Issue Critical Metal Minerals in Coal)

► Show Figures

Figure 1

22 pages, 10713 KiB

Open AccessFeature PaperArticle

Imaging of Ancient Microbial Biomarkers within Miocene Dolomite (Kuwait) Using Time-of-Flight Secondary Ion Mass Spectrometry

by Ammar S. Alibrahim, Rana N. S. Sodhi, Michael J. Duane and Maria Dittrich

Minerals 2023, 13(7), 968; https://doi.org/10.3390/min13070968 - 21 Jul 2023

Cited by 1 | Viewed by 1370

Abstract

Time-of-Flight–Secondary Ion Mass Spectrometry (ToF-SIMS) using a bismuth liquid metal ion source was utilized to characterize and image microbial biomarkers within dolomite from early-middle Miocene coastal mud volcano outcrops in Kuwait. ToF-SIMS analysis revealed biomarkers of ancient microbial consortia of sulfate reducers and [...] Read more.

Time-of-Flight–Secondary Ion Mass Spectrometry (ToF-SIMS) using a bismuth liquid metal ion source was utilized to characterize and image microbial biomarkers within dolomite from early-middle Miocene coastal mud volcano outcrops in Kuwait. ToF-SIMS analysis revealed biomarkers of ancient microbial consortia of sulfate reducers and methane oxidizers participating in the anaerobic oxidation of methane. The identified lipid biomarkers comprised 17α(H),21β(H)-Norhopane, Hop-17(21)-ene or Hop-22(29)-ene (diploptene), non-isoprenoidal dialkyl glycerol diethers (DAGEs), and Diacylglycerol esters (DGs). The ion µ-scale images of carbonate rocks showed two characteristic styles: (1) high signal intensity of dolomite, halite, and biomarkers, where the biomarkers demonstrate a distinctive co-localization pattern with both dolomite and halite; and (2) a lack of dolomite, halite low signal intensity, and an absence of biomarker co-localization patterns. Our results highlight three remarkable observations. Firstly, the concomitance of dolomite and halite suggests a common source of magnesium and sodium supply, likely from the hypersaline Al-Subiya sabkha. This emphasizes the importance of hypersaline seawater for dolomite formation. Secondly, microbial biomarkers correspond to methane- and sulfate-rich conditions under which dolomite was formed. Lastly, the high intensity of biomarker signals and their association with dolomite and halite indicate that the consortia involved in dolomite formation have preferences for high-salinity conditions. The three observations align with previous studies that have highlighted the importance of methane-sulfate redox, high salinity, and halophilic microbes for dolomite formation. This work is the first to acknowledge ancient microbial biomarkers within Miocene dolomite in Kuwait, which aims to broaden the understanding of the biogeochemical processes triggering dolomite formation in similar environments and ancient geologic settings. Full article

(This article belongs to the Special Issue Biomineralization and Biominerals: Lessons from Mineral-Producing Organisms)

► Show Figures

Figure 1

20 pages, 5881 KiB

Open AccessArticle

Trapiche-like Quartz from Dongwuqi Area, Inner Mongolia, China

by Ling Jiang and Yingxin Liu

Minerals 2023, 13(7), 967; https://doi.org/10.3390/min13070967 - 21 Jul 2023

Cited by 1 | Viewed by 1269

Abstract

Trapiche-like quartz, which is scarcely reported, has a unique texture with a core, six arms, and quartz growth sectors. This study is based on six trapiche-like quartz from the Dongwuqi area, Inner Mongolia, China. Many experiments have been carried out to investigate the [...] Read more.

Trapiche-like quartz, which is scarcely reported, has a unique texture with a core, six arms, and quartz growth sectors. This study is based on six trapiche-like quartz from the Dongwuqi area, Inner Mongolia, China. Many experiments have been carried out to investigate the basic gemological characteristics, crystal structures, and chemical compositions. Magnification observation has demonstrated that the texture is due to the distribution of white-colored chalcedony in growth sectors. Spherical and black inclusions have been identified as iron oxides by Raman spectra and EPMA. EPMA and LA-ICP-MS data have shown that the samples were grown in an acidic environment with an average medium-high temperature of 325 °C. Combined with the crystal growth theories and infrared experiments, we propose that the trapiche-like texture is the result of dislocation glide, which is caused by the existence of water and changes in temperature. Full article

(This article belongs to the Special Issue Formation of Gemstones and Geology of Gem Deposits)

► Show Figures

Figure 1

20 pages, 7535 KiB

Open AccessArticle

Ultimate Pit-Limit Optimization Algorithm Enhancement Using Structured Query Language

by Gonzalo Ares, César Castañón Fernández and Isidro Diego Álvarez

Minerals 2023, 13(7), 966; https://doi.org/10.3390/min13070966 - 20 Jul 2023

Viewed by 1396

Abstract

Three-dimensional block models are the most widely used tool for the study and evaluation of ore deposits, the calculation and design of economical pits, mine production planning, and physical and numerical simulations of ore deposits. The way these algorithms and computational techniques are [...] Read more.

Three-dimensional block models are the most widely used tool for the study and evaluation of ore deposits, the calculation and design of economical pits, mine production planning, and physical and numerical simulations of ore deposits. The way these algorithms and computational techniques are programmed is usually through complex C++, C# or Python libraries. Database programming languages such as SQL (Structured Query Language) have traditionally been restricted to drillhole sample data operation. However, major advances in the management and processing of large databases have opened up the possibility of changing the way in which block model calculations are related to the database. Thanks to programming languages designed to manage databases, such as SQL, the traditional recursive traversal of database records is replaced by a system of database queries. In this way, with a simple SQL, numerous lines of code are eliminated from the different loops, thus achieving a greater calculation speed. In this paper, a floating cone optimization algorithm is adapted to SQL, describing how economical cones can be generated, related and calculated, all in a simple way and with few lines of code. Finally, to test this methodology, a case study is developed and shown. Full article

(This article belongs to the Section Mineral Deposits)

► Show Figures

Graphical abstract

18 pages, 1821 KiB

Open AccessArticle

The Perturbation of the Guadalupian Marine Environment Triggered by Early-Stage Eruption of the Emeishan Large Igneous Province: Rare Earth Element and Sr-Nd Isotope Evidence from Zunyi Manganese Deposit, South China

by Hao Yan, Daohui Pi, Lingang Xu and Kai Sun

Minerals 2023, 13(7), 965; https://doi.org/10.3390/min13070965 - 20 Jul 2023

Viewed by 952

Abstract

Pure marine chemical sediments are archives of geochemical proxies for the composition of seawater and may provide information about the ancient hydrosphere–atmosphere system. The early stage of the Emeishan large igneous province (ELIP) was characterized by the subaqueous eruption of mafic igneous rocks [...] Read more.

Pure marine chemical sediments are archives of geochemical proxies for the composition of seawater and may provide information about the ancient hydrosphere–atmosphere system. The early stage of the Emeishan large igneous province (ELIP) was characterized by the subaqueous eruption of mafic igneous rocks around the J. altudaensis zone of the Capitanian Stage that has been proposed to have contributed to the Guadalupian mass extinction. However, detailed mechanisms and the impact of the eruption on the Guadalupian marine environment have yet to be assessed. Here, to examine the Guadalupian marine environment, we studied major and trace element concentrations, particularly rare earth element and yttrium data, along with high-precision Sr-Nd isotope ratios, of three types of Mn ores (i.e., clastic, massive, and oolitic) and siliceous limestones from the Zunyi Mn deposit in South China formed following the early-stage eruption of the ELIP. Our results indicate that the clastic Mn ores contain notable detrital mafic aluminosilicates. In contrast, the massive and oolitic Mn ores and siliceous limestones preserved the pristine geochemical signatures of the Middle–Late Permian seawater characterized by distinctly low (⁸⁷Sr/⁸⁶Sr)_i and high ε_Nd(t) values. These data indicate a strong impact of the early-stage submarine eruptions of the ELIP on the marine environment in South China and worldwide, likely through intensive seawater–rock interaction. Full article

(This article belongs to the Special Issue Isotope Geochemical Analysis Technology and Its Applications)

► Show Figures

Figure 1

11 pages, 3543 KiB

Open AccessArticle

High-Speed Dynamic Camera Analysis of the Hematite Floc–Bubble Mineralization Process

by Fusheng Niu, Yuying Chen, Jinxia Zhang and Zhenjia Chang

Minerals 2023, 13(7), 964; https://doi.org/10.3390/min13070964 - 20 Jul 2023

Viewed by 667

Abstract

The most efficient method for recovering microfine-grained hematite ore is flocculation flotation. Because the flocculation–bubble mineralization process in flocculation flotation has yet to be well investigated, a series of experimental investigations on hematite flocculation–bubble were conducted to better understand the hematite flocculation–bubble interaction [...] Read more.

The most efficient method for recovering microfine-grained hematite ore is flocculation flotation. Because the flocculation–bubble mineralization process in flocculation flotation has yet to be well investigated, a series of experimental investigations on hematite flocculation–bubble were conducted to better understand the hematite flocculation–bubble interaction process. The results show that as the flocculant size increases, the sliding time of the flocculant to the bottom of the bubble shortens, and the change in the instantaneous dynamic velocity is slower when the diameter of the fixed bead is 544.52 μm, which is more favorable to flocculant adhesion on the bubble surface. When the bubble diameter is 544.52 μm and the floc diameter is 39.65 μm, the shortest time is 49.5 ms, and the maximum value of instantaneous velocity is 28.67 μm·ms⁻¹. According to the force analysis of the floc on the bubble surface, when the particle size of the floc is 39.65 μm and the bubble diameter is 544.52 μm, the desorption force is 4.99 × 10⁻³ mN·m⁻¹ larger, and the adhesion force is 7.08 × 10⁻⁴ mN·m⁻¹ smaller. The smaller Bond constant Bo′ is 0.14. In that moment, the flocs in the sodium solution are very stable. Full article

(This article belongs to the Topic Green Low-Carbon Technology for Metalliferous Minerals)

► Show Figures

Figure 1

21 pages, 17113 KiB

Open AccessArticle

Petrogenesis of Early Cretaceous Granitoids in the Qingdao Area, Jiaodong Peninsula: Constraints from Zircon U–Pb Ages, Geochemistry and Sr–Nd–Hf Isotopes

by Yi Ding, Xuejiao Bu, Hong Zhao, Shihua Zhong and Ming Liu

Minerals 2023, 13(7), 963; https://doi.org/10.3390/min13070963 - 20 Jul 2023

Viewed by 812

Abstract

The Jiaodong Peninsula is located on the junction of the North China Craton (NCC) and South China Block (SCB), where Mesozoic igneous rocks are widespread. However, the petrogenesis and tectonic settings for these Mesozoic igneous rocks are still controversial. In this study, we [...] Read more.

The Jiaodong Peninsula is located on the junction of the North China Craton (NCC) and South China Block (SCB), where Mesozoic igneous rocks are widespread. However, the petrogenesis and tectonic settings for these Mesozoic igneous rocks are still controversial. In this study, we present detailed geochronological and geochemical analyses of quartz monzonite, monzogranite, syenogranite, and alkali feldspar granite in the Qingdao area, east of the Jiaodong Peninsula, to constrain their petrogenesis and tectonic setting. Zircon U–Pb dating shows that they mainly formed in the Early Cretaceous (120.5–113.1 Ma). Quartz monzonite exhibits adakitic geochemical features (e.g., low Y and high Sr/Y). Combined with its Sr–Nd–Hf isotopic features, we suggest that quartz monzonite may have been produced by the partial melting of phengite-bearing eclogites at the base of the thickened continental crust of the NCC. In contrast, monzogranite and syenogranite exhibit I-type granite affinities, whereas alkali feldspar granite exhibits features consistent with A-type granite. The strongly negative ε_Hf(t) and ε_Nd(t) values of the I-type rocks indicate that they were most likely produced through partial melting of granitic gneisses from the NCC, whereas A-type magmas may be formed through fractional crystallization from the non-adakitic granitic magma. Combined with previous studies, we suggest that these granitoids were formed in a lithospheric extensional setting via the rollback of the subducted Paleo-Pacific slab, which resulted in the reworking of the deep crust beneath the Sulu ultrahigh-pressure metamorphic belt. Full article

(This article belongs to the Special Issue Isotope Geochemical Analysis Technology and Its Applications)

► Show Figures

Figure 1

13 pages, 2998 KiB

Open AccessReview

Abundance and Genetic Significance of Lithium in Karst-Type Bauxite Deposits: A Comparative Review

by Maria Economou-Eliopoulos and Christos Kanellopoulos

Minerals 2023, 13(7), 962; https://doi.org/10.3390/min13070962 - 19 Jul 2023

Cited by 1 | Viewed by 1655

Abstract

Palaeo weathering during the Cretaceous–Eocene interval is most favorable for bauxitization, i.e., transport and deposition in traps on the karstified surfaces of the Mediterranean karst bauxite belt, including the Parnassos–Ghiona bauxite deposit. Resources of lithium (Li), a critical metal of strategic significance in [...] Read more.

Palaeo weathering during the Cretaceous–Eocene interval is most favorable for bauxitization, i.e., transport and deposition in traps on the karstified surfaces of the Mediterranean karst bauxite belt, including the Parnassos–Ghiona bauxite deposit. Resources of lithium (Li), a critical metal of strategic significance in karst-type bauxite deposits, have attracted significant attention in recent years. Due to the discovery of the Li enrichment in certain karstic bauxite deposits in Europe and particularly in China, this review study is focused on the unexplored Li content in the Parnassos–Ghiona (Greece) bauxite deposit, aiming to improve the understanding of the major controlling factors for their origin and enrichment of critical metals. The presence of thin (up to 50 cm) pyrite-bearing coal seams and carbonaceous facies on top of the Parnassos–Ghiona bauxite deposit, at the transition between B3 (the youngest) bauxite horizon and the occurrence of multicolor bauxite ores reflecting a multistage evolution and changes in the mineralogy and geochemistry, is a common feature with other bauxite deposits in Europe and elsewhere. The organic matter, such as microorganisms in coal layers and carbonaceous layers (derived from plants and algae growing in paleo-mires after a regression of the sea), contains Li, which is derived from seawater, as suggested by a positive correlation with B (a seawater component as well). The available geological, mineralogical, and geochemical data highlight the particular significance of coal layers and carbonaceous layers overlying bauxite bodies as a driving force for redox reactions and as a source of Li in the exploration of karst-type bauxite deposits. Full article

(This article belongs to the Special Issue Geochemical and Mineralogical Characteristics of Palaeokarstic Bauxite Deposits)

► Show Figures

Figure 1

27 pages, 17148 KiB

Open AccessFeature PaperArticle

The INOVMineral Project’s Contribution to Mineral Exploration—A WebGIS Integration and Visualization of Spectral and Geophysical Properties of the Aldeia LCT Pegmatite Spodumene Deposit

by Joana Cardoso-Fernandes, Douglas Santos, Cátia Rodrigues de Almeida, Julia Tucker Vasques, Ariane Mendes, Ricardo Ribeiro, Antonio Azzalini, Lia Duarte, Rui Moura, Alexandre Lima and Ana C. Teodoro

Minerals 2023, 13(7), 961; https://doi.org/10.3390/min13070961 - 19 Jul 2023

Cited by 3 | Viewed by 1992

Abstract

Due to the current energetic transition, new geological exploration technologies are needed to discover mineral deposits containing critical materials such as lithium (Li). The vast majority of European Li deposits are related to Li–Cs–Ta (LCT) pegmatites. A review of the literature indicates that [...] Read more.

Due to the current energetic transition, new geological exploration technologies are needed to discover mineral deposits containing critical materials such as lithium (Li). The vast majority of European Li deposits are related to Li–Cs–Ta (LCT) pegmatites. A review of the literature indicates that conventional exploration campaigns are dominated by geochemical surveys and related exploration tools. However, other exploration techniques must be evaluated, namely, remote sensing (RS) and geophysics. This work presents the results of the INOVMINERAL4.0 project obtained through alternative approaches to traditional geochemistry that were gathered and integrated into a webGIS application. The specific objectives were to: (i) assess the potential of high-resolution elevation data; (ii) evaluate geophysical methods, particularly radiometry; (iii) establish a methodology for spectral data acquisition and build a spectral library; (iv) compare obtained spectra with Landsat 9 data for pegmatite identification; and (v) implement a user-friendly webGIS platform for data integration and visualization. Radiometric data acquisition using geophysical techniques effectively discriminated pegmatites from host rocks. The developed spectral library provides valuable insights for space-based exploration. Landsat 9 data accurately identified known LCT pegmatite targets compared with Landsat 8. The user-friendly webGIS platform facilitates data integration, visualization, and sharing, supporting potential users in similar exploration approaches. Full article

(This article belongs to the Special Issue Novel Methods and Applications for Mineral Exploration, Volume II)

► Show Figures

Figure 1

18 pages, 5526 KiB

Open AccessArticle

Densification Mechanisms and Pore Evolution Analysis of a Tight Reservoir: A Case Study of Shan-1 Member of Upper Paleozoic Shanxi Formation in SW Ordos Basin, China

by Ling Xiao, Leilei Yang, Xuwen Zhang, Xijuan Guan and Qinlian Wei

Minerals 2023, 13(7), 960; https://doi.org/10.3390/min13070960 - 19 Jul 2023

Cited by 2 | Viewed by 1036

Abstract

This comprehensive analysis investigated the causes of formation densification in the Shan-1 Member tight reservoir in the southwestern Ordos Basin. The study aimed to mitigate exploration and development risks by examining petrological characteristics, reservoir performance, pore characteristics, and pore evolution. Various techniques were [...] Read more.

This comprehensive analysis investigated the causes of formation densification in the Shan-1 Member tight reservoir in the southwestern Ordos Basin. The study aimed to mitigate exploration and development risks by examining petrological characteristics, reservoir performance, pore characteristics, and pore evolution. Various techniques were employed, including thin-section casting, scanning electron microscopy, and analysis of porosity and permeability. By establishing the relationship between visualized reservoir porosity and thin slice porosity, along with employing mechanical compaction correction methods and the principle of “back stripping by inversion,” the recovery of paleophysical properties in tight sandstone reservoirs was conducted. Additionally, the research integrated diagenetic evolution sequences and the recovery of paleophysical properties to analyze the origins of reservoir densification and pore evolution in the Shan-1 Member. The results suggest that compaction is the primary factor contributing to reservoir densification, with burial depth playing a crucial role in determining the intensity of compaction. Cementation, particularly associated with illite, emerged as a significant influence on reservoir densification, while low dissolution also contributed to the densification process. The densification of the Shan-1 reservoir in the study area was estimated to have occurred during the Early Jurassic, approximately 195 Ma. These research findings not only enhance the understanding of the Shan-1 reservoir but also provide valuable insights for predicting tight reservoirs and improving the efficiency of oil and gas production. Full article

(This article belongs to the Special Issue Mineralogy, Geochemistry, and Sedimentary Geology of Lacustrine Basins)

► Show Figures

Figure 1

14 pages, 4166 KiB

Open AccessArticle

Nature of Pigments in Orange and Purple Coloured Chinese Freshwater Cultured Pearls: Insights from Experimental Raman Spectroscopy and DFT Calculations

by Chaoyang Chen, Jing Yu, Chuting Zhang, Xu Ye and Andy H. Shen

Minerals 2023, 13(7), 959; https://doi.org/10.3390/min13070959 - 18 Jul 2023

Cited by 1 | Viewed by 1324

Abstract

Pearls, a well-known organic gemstone, are popular for their attractive lustre and rich colour. The pigmentation and colour of pearls have never been clearly explained. Understanding the pigments and colour origin of pearls can be a guide for artificial cultivation and rational conservation. [...] Read more.

Pearls, a well-known organic gemstone, are popular for their attractive lustre and rich colour. The pigmentation and colour of pearls have never been clearly explained. Understanding the pigments and colour origin of pearls can be a guide for artificial cultivation and rational conservation. In this study, Chinese freshwater cultured pearls were collected as research samples. The appearance and colour characteristics of pearls were characterised using D65 standard light source photography and UV–Vis spectroscopy, the molecular structure of the pigments in the pearls was characterised using Raman spectroscopy, and Density Functional Theory (DFT) calculations were used to reveal the characteristics of the pigments in the pearls in terms of molecular structure and electronic excitation. It was proposed that freshwater pearls are coloured with polyene pigments, with the chain length of the polyene determining the type of colour and the concentration of the polyene determining the colour intensity of the pearl. The HOMO–LUMO transition of conjugated polyenes is intrinsically responsible for the colour of pearls. Many colour-rich biominerals also have similar Raman spectral features to pearls, and this study has wider implications for understanding the nature of pigments and their colour origins. Full article

(This article belongs to the Special Issue Gemstone Analysis by Spectroscopy and Microscopy, Volume II)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Minerals, Volume 13, Issue 7 (July 2023) – 154 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI