Mineral Deposits Research Articles

Post-Collisional Tectonomagmatic Evolution, Crustal Reworking and Ore Genesis along a Section of the Southern Variscan Belt: The Variscan Mineral System of Sardinia (Italy)

Since the early Paleozoic, numerous metallogenic events produced in the Sardinian massif a singular concentration of mineral deposits of various kinds. Among them, the Variscan metallogenic peak represents a late Paleozoic phase of diffuse ore formation linked to the tectonomagmatic evolution of the Variscan chain. Two main classes of ores may primarily be attributed to this peak: (1) mesothermal orogenic-type As-Au ± W ± Sb ores, only found in E Sardinia, and (2) intrusion-related Sn-W-Mo-F and base metals-bearing ores found in the whole Sardinian Batholith, but mainly occurring in central–south Sardinia. Both deposit classes formed diachronously during the Variscan post-compressional extension. The orogenic-type ores are related to regional-scale flows of mineralizing fluids, and the intrusion-related ores occur around fertile intrusions of different granite suites. Metallogenic reconstructions suggest almost entirely crustal processes of mineralization without a significant contribution from the mantle. We summarized these processes with a holistic approach and conceptualized the Sardinian Variscan Mineral System (SVMS), a crustal-scale physical system of ore mineralization in the Sardinian basement. The SVMS required suitable metal sources in the crust and diffuse crustal reworking triggered by heat that allowed (a) the redistribution of the original metal budget of the crust in magmas by partial melting and (b) the production of metal-bearing fluids by metamorphic dehydration. Heat transfer in the Sardinian Variscan crust involved shear heating in lithospheric shear zones and the role of mantle uplift as a thermal engine in an extensional tectonic setting. Lithospheric shear zones acted as effective pathways in focusing fluid flow through a large-scale plumbing system into regional-scale structural traps for ores. Pre-Variscan metal sources of metallogenic relevance may have been (1) the magmatic arc and magmatic arc-derived materials of Ordovician age, extensively documented in E Sardinia crust, and (2) an inferred Precambrian crystalline basement lying under the Phanerozoic crustal section, whose presence has been assumed from geophysical data and from petrological and geochemical characteristics of granite suites. At shallower crustal levels, important contributions of metals may have come from pre-Variscan ore sources, such as the Pb-Zn MVT Cambrian ores of SW Sardinia or the REE-bearing Upper Ordovician paleoplacers of E Sardinia.

Composite Spheroid-Laden Bilayer Hydrogel for Engineering Three-Dimensional Osteochondral Tissue.

A combination of hydrogels and stem cell spheroids has been used to engineer three-dimensional (3D) osteochondral tissue, but precise zonal control directing cell fate within the hydrogel remains a challenge. In this study, we developed a composite spheroid-laden bilayer hydrogel to imitate osteochondral tissue by spatially controlled differentiation of human adipose-derived stem cells. Meticulous optimization of the spheroid-size and mechanical strength of gelatin methacryloyl (GelMA) hydrogel enables the cells to homogeneously sprout within the hydrogel. Moreover, fibers immobilizing transforming growth factor beta-1 (TGF-β1) or bone morphogenetic protein-2 (BMP-2) were incorporated within the spheroids, which induced chondrogenic or osteogenic differentiation of cells in general media, respectively. The spheroids-filled GelMA solution was crosslinked to create the bilayer hydrogel, which demonstrated a strong interfacial adhesion between the two layers. The cell sprouting enhanced the adhesion of each hydrogel, demonstrated by increase in tensile strength from 4.8 ± 0.4 to 6.9 ± 1.2 MPa after 14 days of culture. Importantly, the spatially confined delivery of BMP-2 within the spheroids increased mineral deposition and more than threefold enhanced osteogenic genes of cells in the bone layer while the cells induced by TGF-β1 signals were apparently differentiated into chondrocytes within the cartilage layer. The results suggest that our composite spheroid-laden hydrogel could be used for the biofabrication of osteochondral tissue, which can be applied to engineer other complex tissues by delivery of appropriate biomolecules.

Semantic information extraction and search of mineral exploration data using text mining and deep learning methods

Large-scale mineral resource reports offer a wealth of information for geological knowledge mining and mineral explorers’ knowledge discovery. The geological conditions in which mineral deposits develop may be learned a great deal from these mineral exploration reports. Mineral exploration data may be queried and aggregated to effectively mitigate future exploration risks and reduce costs. However, due to the reports being presented in unstructured textual format, it becomes challenging to extract valuable geological data without manually scanning through a vast number of reports. This laborious process poses difficulties for geologists. To address this issue, this paper proposes a system that extracts a set of geologically relevant keywords/keyphrases of each chapter from each mineral exploration reposts using latent Dirichlet allocation (LDA), develops a topic graph, recognizes the geological entity and related relations for constructing a knowledge graph, and uses visualization of those graphs (e.g., topic graphs and knowledge graphs) to explore the contents of the report. The text mining and machine learning technique described here serves as the foundation for future research into incorporating semantic analysis into geological information extraction. The findings of this study show how automated text analysis may help with the quick processing of huge quantities of reports in order to identify target mineral systems and their related geological location and rock mineral composition. The suggested approaches can quickly and reliably convert mineral exploration data (e.g., text, figure, and table) into a structured form, which is a hitherto untouched field in geological knowledge mining.

2024 IGWS calendar

The annual Indiana Geological and Water Survey calendar focuses on an area of Survey research, interest or history. The topic of the 2024 calendar is critical minerals, earth materials that are essential to economic prosperity and national security. They include metals like lithium, nickel, and cobalt, rare earth elements, and other valuable minerals. Critical minerals are found in small concentrations, often with other mineral deposits, making them difficult and expensive to extract. The U.S. is increasingly dependent upon foreign sources of the processed versions of critical minerals. China controls the market for processing and refining, which leaves most of the world reliant upon imports.

EFFECT OF PPARG INHIBITION ON HUMAN BMSC CELL FATE

The effects of dexamethasone (dex), during in vitro human osteogenesis, are contrasting. Indeed, dex downregulates SOX9 during osteogenic differentiation of human bone marrow mesenchymal stromal cells (HBMSCs). However, dex also promotes PPARG expression, resulting in the formation of adipocyte-like cells within the osteogenic monolayers. The regulation of both SOX9 and PPARG seems to be downstream the transactivation activity of the glucocorticoid receptor (GR), thus the effect of dex on SOX9 downregulation is indirect. This study aims at determining whether PPAR-γ regulates SOX9 expression levels, as suggested by several studies.HBMSCs were isolated from bone marrow of patients with written informed consent. HBMSCs were cultured in different osteogenic induction media containing 10 or 100 nM dex. Undifferentiated cells were used as controls. Cells were treated either with a pharmacological PPAR-γ inhibitor T0070907 (donors n=4) or with a PPARG-targeting siRNA (donors n=2). Differentiation markers or PPAR-γ target genes were analysed by RT-qPCR. Mineral deposition was assessed by ARS staining. Two-way ANOVA followed by a Tukey's multiple comparison test compared the effects of treatments.At day 7, T0070907 downregulated ADIPOQ and upregulated CXCL8, respectively targets of PPAR-γ-mediated transactivation and transrepression. RUNX2 and SOX9 were also significantly downregulated in absence of dex. PPARG was successfully downregulated by siRNA. ADIPOQ expression was also inhibited, while CXCL8 did not show any significant difference between siRNA treatment groups. RUNX2 was downregulated by the PPARG-siRNA treatment in presence of 100 nM dexamethasone, while SOX9 levels were not affected. ARS showed no change in the mineralization levels when PPARG expression or activity was inhibited.Understanding how dex regulates HBMSC differentiation is of pivotal importance to refine current in vitro models. These results suggest that PPARG does not mediate SOX9 downregulation. Unexpectedly, RUNX2 expression was also unaltered or even downregulated after PPAR-γ inhibition.Acknowledgements: AO Foundation, AO Research Institute (CH) and PRIN 2017 MUR (IT) for financial support.

CPPD and Associated Crystals in Clinically Diagnosed Chondrocalcinosis: A Clinicopathological Study of 20 Patients

Introduction: Chondrocalcinosis (Ch-C), induced by calcium pyrophosphate dihydrate crystals (CPPD) [Ca2P2O7.2H2O] is considered as a distinct metabolic disease and a well-defined clinical entity, with characteristic clinical manifestations and symptoms. This study used previously found method by the author .i.e, non-staining approach to discover crystal deposits in patients with clinically diagnosed Ch-C, to find a possible correlation between coexisting crystals, and to assess the role of coexistent crystals in inflammatory cellular processes of joints. Patients and methods: There were forty (40) surgical specimens that had been traditionally processed from 16 patients who had been clinically diagnosed with Ch-C. Results: In unstained tissue sections CPPD crystals were found in 22 of 40 samples of all 16 patients. Beside the CPPD crystals calcium hydroxyapatite (HA) [Ca5(PO4)3(OH)] crystals were found in 26 tissue samples of all 16 patients, cholesterol (CC) [C27H46O] in 23 tissue samples of 12 patients, and crystalline liquid lipid droplets (CL) in 11 tissue samples of 5 patients. More or less amorphous deposits of calcium carbonate [CaCO3] and/or calcium phosphate [Ca3(PO4)2] were present alongside CPPD and the contemporaneous crystals. There was a significant and positive correlation between prevalence of CPPD and HA. The connection between inflammatory cellular infiltration and CPPD, HA, CC or CL crystals surrounded by mineral deposits was not significant. Conclusions: The non-staining approach is a practical, low-tech way to find CPPD, HA, CC, and other crystals (with or without CL). The positive and significant correlation between CPPD and HA support the earlier premise that CPPD and HA represent basically an identical metabolic disorder). CPPD and/or HA crystals can provoke inflammatory processes responsible for the clinical symptoms, but the variable amounts of amorphous minerals enclose (isolate) the crystals, and can reduce or eliminate the inflammatory reaction. The authors assume that CC (with or without CL) is an associated phenomenon (concomitant fat metabolic malady) without direct cause of inflammation, and is not responsible for clinical symptoms of crystal induced arthropathies.

Corilagin functionalized decellularized extracellular matrix as artificial blood vessels with improved endothelialization and anti-inflammation by reactive oxygen species scavenging

Abstract The performance of biological-originated blood vessels in clinical remains disappointing due to fast occlusion caused by acute thrombosis or long-standing inflammation. How to prevent rapid degradation and inhibit acute inflammation but maintain their high bioactivity is still a significant challenge. As a bioactive polyphenol in various traditional Chinese medicine, Corilagin (Cor) exhibits excellent anticoagulant, anti-inflammatory and rapid ROS consumption properties. Inspired by abundant supramolecular interactions in organisms, we selected it to crosslink tissues via purely H-bonds to simulate these natural interactions without introducing potential toxic aldehyde or carboxyl groups. Results show that 2 mg/ml was selected as the optimal Cor concentration to form a stable crosslinking network (FI > 95%) and effectively delay their degradation. Cor modification not only enhances ECs adhesion and monolayer function via accelerating VEGF and TGF-β secretion but also promotes macrophage transformation from pro-inflammatory M1 phenotype to anti-inflammatory M2 ones. In vitro and ex-vivo studies implied that Cor-crosslinked samples exhibited low platelet accumulation and decreased thrombin generation. In vivo evaluation further confirmed that Cor-introducing could effectively consume ROS, thus exhibiting rapid endothelialization, suppressed inflammation and reduced mineral deposition. Overall, Cor crosslinking provided a bright future for blood vessels’ long-term patency and adapted to various blood-contacting surfaces.

Категории пространства и времени в решении проблем будущего горного дела

ions, and challenges that must be taken into account when designing the future life of society. The object of the research is mining. The purpose of the study is to provide integrated directions for the development of the future of mining related to the content of the subject of Earth Science, robotization of human labor, environmental protection and research on the formation of new mineral deposits. The objectives of the research are based on scientific knowledge about mining, and using philosophical reflections (laws of the development of the world, society and mining, moral categories and values of mining engineers) and debatable issues of political science (political processes and phenomena), to answer a number of pressing questions related to the future of mining Methodology and the research methods are based on a normative-value, systemic, comparative and interdisciplinary integrated approach (mining, philosophy, political science), which allows the author to comprehensively explore ways to solve the problems of the future of mining. The work has also been carried out on the basis of general scientific principles of objectivity, consistency with the use of general scientific and private scientific research methods: analysis, synthesis, generalization, induction and deduction. Research results are as follows: it is necessary to develop a concept for the mining development in the coming years; increased attention is required to the organization of science and education, since the mining strategy is largely the basis for the development and existence of our country and its security; mining science should offer new revolutionary technologies for exploration, extraction and processing of mineral raw materials; increase the pace of development of branch mining sciences; effective and updated training of mining engineers with a large amount of information, knowledge, skills and analytical skills when making decisions in controversial and crisis situations; a reasonable concept of human behavior in modern conditions; conducting research on the formation of new mineral deposits.

Century of Laskarev's landmark contribution to Paratethys Science

Laskarev?s seminal contribution to the recognition and elucidation of the Paratethys Sea within geological discourse stands as one of the pivotal milestones in our understanding of Neogene European paleogeography. Although the Neogene marine deposits of central and southeastern Europe were known before him, he greatly facilitated discourse and communication about them by giving them a paleogeographical name. By officially introducing the term Paratethys and meticulously delineating its geographic extent and history, Laskarev unveiled profound insights into past climates, environments, and biotic evolution across Central and Eastern Europe. His work provided a solid foundation for subsequent investigations of the Paratethys region. Moreover, beyond its scientific intrigue, the Paratethys Sea holds considerable economic importance due to its rich geo logical endowment. This reservoir of resources includes hydrocarbon reserves, mineral deposits, and a burgeoning potential for geotourism. While substantial strides have been made in unraveling its mysteries, the Paratethys Sea still beckons further exploration, promising untapped realms of knowledge and economic opportunity.

Sea Bed Mining

The seabed is surely one of the last mining frontiers on earth remaining for mankind, to extract economic mineral deposits. It is hence imperative that India with its Obvious Geological Potential (OGP) area on the land surface amounting to 0.57 million km, for which baseline geoscience data has been generated and mineral exploration activities are ongoing, needs to be supplemented with mineral wealth on our sea beds, within our Territorial Waters (TW) and Exclusive Economic Zone (EEZ). Studies by the Geological Survey of India (GSI) and other agencies for mineralized horizons in the terrestrial OGP areas have been a continuous process. The baseline geoscience and mineral exploration data are published regularly by GSI and Indian Bureau of Mines (IBM) and made available to respective stakeholders. India has a 2.02 million km area under its TW and EEZ. Our East and West Coasts of the Peninsular India are endowed with phosphate, manganese nodules, lime mud and monazite sands with rare earth elements (REE) and thorium that have been surveyed by the Marine and Coastal Survey Division (MCSD) of the GSI with their research vessels to establish the potentiality. According to the data available, 1,53,996 million tons of lime mud within the EEZ off Gujarat and Maharashtra coasts, 745 million tons of construction grade sand, off Kerala coast, 79 million tons of heavy mineral placers in the inner-shelf and mid-shelf, off Odisha, Andhra Pradesh, Kerala, Tamil Nadu and Maharashtra, phosphorite in the Eastern and Western continental margins, polymetallic ferromanganese nodules and crusts in Andaman Sea and Lakshadweep Sea have been reported. The CSIR- National Institute of Oceanography has been embarking on research for seabed mineral deposits. The Offshore Areas Mineral (Development and Regulation) Amendment Bill, 2023, passed by Lok Sabha on 01.08.2023, has amendments to the Offshore Areas Mineral (Development and Regulation) Act, 2002, OAMDR Act (Ministry of Mines, Govt. of India, 2002). It envisages major initiatives to allow auction of mineral blocks 45° X 45° (latitude and longitude) in respect of any mineral or prescribed group of associated minerals, under one or more operating rights (taken together). The Act has a provision for setting up of a non-lapsable Offshore Areas Mineral Trust to maintain a fund under the Public Account of India. This fund will be financed by a yet to be determined, additional levy on the production of offshore minerals that will be used for exploration, research, disaster relief and for mitigation of adverse impacts of seabed mining. We have the National Exploration Trust and the District Mineral Foundation Trust funds, to which royalties are paid by stakeholders for onshore mining.

Biomimetic Materials for Regenerative Medicine: Design and Applications

Bio mimetic materials have shown great potential for tissue engineering and regenerative medicine as they can mimic the natural extracellular matrix (ECM) of tissues and organs. The ECM is a complex network of proteins, glycosaminoglycans, and other bio molecules that provide structural support to cells and regulate their behaviour. Bio mimetic materials can be designed to replicate the biochemical and biophysical properties of the ECM, creating an environment that promotes cell adhesion, proliferation, differentiation, and tissue regeneration. There are different classes of bio mimetic materials, including natural and synthetic polymers, as well as inorganic materials such as Hydroxyapatite and ceramics. Polymers made from nature that assist with with cell growth and differentiation, like collagen, which is fibrin, and hyaluronic acid, for instance, have been utilised extensively in tissue engineering. Both the physical and chemical characteristics of synthetic polymers, which include polyethylene glycol, also known as PEG, and poly lactic acid (PLA), can be modified to satisfy the needs of different tissues. Inorganic materials such as hydroxyapatite and ceramics can mimic the mineralized ECM of bone and tooth tissues, providing a scaffold for cell attachment and mineral deposition. Recent advances in the field of bio mimetic materials include the use of nanotechnology and 3D printing to create complex structures with precise control over their size, shape, and mechanical properties. Nanoparticles and nano fibers can be incorporated into bio mimetic materials to enhance their mechanical strength, surface area, and bioactivity. 3D printing can be used to create customized scaffolds that match the shape of the target tissue, allowing for more effective tissue regeneration.

Soil Survey and Lithogeochemical Techniques in Mineral Exploration

This paper investigates the critical roles of soil surveys and lithologic evaluation in identifying potential mineral resources. Soil surveys involve the systematic mapping, examination, description, and classification of soils within a defined area. Through targeted sampling and laboratory analysis, these surveys can reveal the concentration of metals in the soil. By analyzing these metal signatures, geoscientists can infer the underlying geology and identify areas with a higher likelihood of hosting valuable mineral deposits. Lithologic evaluation complements soil surveys by focusing on the physical characteristics of rock units exposed at outcrops, in hand samples, or cores. Observable with the naked eye or a magnifying lens, these characteristics include color, texture, and structural features. Lithogeochemistry, or rock geochemistry, builds upon this foundation by analyzing the chemical composition of the bedrock. This analysis aims to identify spatial patterns of elements typically associated with specific types of mineral deposits. By integrating the findings from soil surveys and lithologic evaluations, geoscientists gain a comprehensive understanding of the subsurface environment, enabling them to prioritize areas for further mineral exploration activities. This paper delves into the fundamentals of these techniques, highlighting their strengths and limitations in the context of mineral resource exploration.

The effects of a mixture of small peptide chelating minerals and inorganic minerals on the production performance and tissue deposition of broiler chickens.

Due to the limited bioavailability of inorganic trace minerals, their utilization in poultry production has led to problems such as environmental contamination and inefficient resource utilization. It was investigated whether replacing inorganic trace minerals (ITM) with a blend of organic small peptide-chelated trace minerals (MIX) would improve production performance, selected biochemical parameters, antioxidant capacity, mineral deposition in liver, heart, and tibia, as well as mineral content in feces of broilers. A total of 432 healthy 21-day-old 817 broilers were randomly divided into 4 groups with 6 replicates per group and 18 chickens per replicate. The control group received a basal diet supplemented with 1,000 mg/kg of inorganic trace minerals as sulfate. The experimental groups received basal diets supplemented with 200, 400, and 600 mg/kg of mixed trace mineral elements (50% sulfate +50% small peptide-chelate) for a trial period of 30 days, divided into two stages: 21-35 days and 36-50 days. The results indicate that on the 50th day, compared with the 1,000 mg/kg ITM group, the levels of serum cholesterol, urea nitrogen, and malondialdehyde in the 200, 400, and 600 mg/kg MIX groups decreased (p < 0.01), while the levels of serum glutathione peroxidase in the 200, 400, and 600 mg/kg MIX groups increased (p < 0.05). Compared to the ITM group, the addition of organic small peptide chelated trace minerals mixed with inorganic trace minerals can reduce the levels of zinc and manganese in feces (p < 0.01). Furthermore, the iron content in the heart and tibia of the 600 mg/kg MIX group also significantly decreased (p < 0.05). There were no differences in growth performance and slaughter performance among the groups (p > 0.05). This study shows that replacing inorganic minerals with low-dose MIX (200, 400, and 600 mg/kg) can reduce the levels of zinc and manganese in feces, with no negative impact on growth and slaughter performance.

Anomalous geoobjects in the Lithosphere of Uzbekistan and their interrelations with ore deposits

One of the priority tasks of the Geological Service of the Republic of Uzbekistan is the study of the paleozoic foundation under the cover of Meso-Cenozoic sediments, mainly using deep seismic sounding profiles, in order to trace known ore fields and mineralized zones in the overlying part of the basement. In recent years, in the laboratory “Structure of the Lithosphere” of the Institute of Geology and Geophysics named after Kh.M. Abdullayev, new data have been obtained as a result of reinterpretation of a complex of geophysical data. In the present work examines the role of anomalous geoobjects with high and low seismic density parameters along deep seismic sounding (DSS) profiles in the Lithosphere of Uzbekistan from the point of view of their spatial correlation with explored deposits of ore minerals. New regional features of the interrelationships between the geological structure of the lithospheric deep structures of Uzbekistan and the spatial distribution of deposits have been identified.

Modifikacije površine zubnih implantata i njihov uticaj na proces oseointegracije

Introduction: Dental implantation is a process of implanting dental implants into the bone of a patient, in places where one or more teeth are missing. For successful implantation, the process of osteointegration has to happen, which means that the dental implant placed in the bone should create a connection with it. The success of the osteointegration process depends on several factors, one of which is a biological modification of the material from which the implant is made. As a failure, it can occur during periimplantitis. Aim: The present study aimed to prove the influence of the foreign body on osteointegration during dental implantation, that is, the cause of peri-implantitis. The subject of our research was the analysis of new, sterile implants and their comparison with fallen, lost implants Materials and methods: For this scientific research we used a scanning electron microscope, which allows a detailed analysis of the implant surface. The analysis was performed on brand new, as well as on failed implants. A Scanning Electron Microscope (SEM) is a type of electron microscope that produces images of a sample by scanning its surface with a focused beam of electrons. Results: As a consequence of the deposition of many minerals (like Mg, and P), a higher wear resistance occurs on the implant surface. Traces of contaminant Na along with carbon, N, Ca, Al and O were also detected on the Ti surface of the failed implants, which are fallen implants. All these elements negatively affect the implantation success and are the cause of unsuccessful implant treatment. Conclusion: Dental implant contamination is a key factor for the success/failure of implantation. Traces of organic and inorganic contaminants can be found, despite the implant cleaning process and surface treatment of Ti, substances such as acid and sand.

The economic situation and ways to solve the environmental problems in the city of Ust-Kut

&lt;p&gt;The Ust-Kutsky district and its center, the Ust-Kut city, have become the fastest growing in the Irkutsk region of Russia in the last decade. Ust-Kut is a very important settlement for the economic development of the northern territories of the Irkutsk region and the southern territories of the Republic of Sakha (Yakutia). The city is a key transport hub, where various types of transport routes converge: railway, aviation, automobile, river, and product pipeline. There are deposits of various minerals near Ust-Kut. The timber mining and timber-processing industries are represented here as much as possible. On the other hand, Ust-Kut is one of the ten most air-polluted cities in the Irkutsk region. Most of the air pollution consists of substances formed as a result of fuel combustion. The unfavorable air regime of the city is influenced by climatic conditions: relatively weak winds and temperature inversions in winter. The oil and gas deposits located nearby may help solve the problem of air pollution by gasification of Ust-Kut. In addition, water and soil pollution have been noted in the city due to technological problems of wastewater disposal, garbage collection, and recycling, as well as certain types of industrial waste processing. Therefore, the main task of the sustainable development of the city is to solve its environmental problems. Ust-Kut's environmental problems are solved at the expense of financial resources from government programs, which are not sufficient. But the tax on mining is completely federal, as these funds do not remain in the territory. Through this research, we have searched for ways to achieve a balance between economic development and environmental well-being in Ust-Kut. Specifically, we have explored additional types of economic activities that are safe for nature and public health. For Ust-Kut, located in the north of Eastern Siberia, it is important to increase the area of green spaces within the central part of the city. The development of a system of parks and squares involves their improvement and the formation of a connection into a single natural framework through linear landscaping objects and connections with urban forest sites. The use of sanitary protection zones around enterprises that emit into the environment will contribute to the formation of a comfortable environment and expand landscaping opportunities.&lt;/p&gt;

Role of faults and tectonic blocks in the Daugiztau gold deposit, Uzbekistan

This article delves into the comprehensive study of geodynamics concerning ore formation within the local area of gold ore mineralization in the central KyzylKum province. The primary focus lies in understanding the influential role of faults and tectonic blocks in the distribution of gold mineralization at the Daugyztau ore field. Geodynamics, as a significant factor in ore formation processes, is driven by external forces and prominently characterized by the dynamic activity of faults and blocks.The central KyzylKum province is renowned for its rich gold deposits, and exploring the underlying geodynamic processes is crucial for deciphering the mechanisms behind the formation and distribution of these valuable mineral resources. The study aims to shed light on the relationship between geodynamic phenomena and gold mineralization within the Daugyztau ore field.One of the key aspects under investigation is the role of faults, which are fractures or discontinuities in the Earth's crust, in controlling the migration and concentration of gold-bearing fluids. These faults act as pathways and conduits for the transportation of hydrothermal fluids, facilitating the deposition of gold and other associated minerals. By analyzing the spatial distribution and characteristics of faults in the area, researchers can gain insights into the geological processes responsible for gold mineralization.

Морфоструктурные особенности минеральных индивидов в рудах золотосульфидного типа. Забайкальский край

The article deal with the results of a study of the morphostructural features of gold sulfide type ore: the forms of ore mineral deposits, their spatial distribution and relationship. The results of crushed ore research are also reflected. The data obtained make it possible to choose of methods for technological ore processing.

Palaeosedimentation in Khotavets lake (Mologa-Sheksna lowland) inferred from the results of explicit GPR survey and drilling data

Late Glacial – Holocene sedimentary record has been obtained from a lake basin at the north of East-European Plain, and AMS14C-dated. Coring results were coupled with the ground penetrating radar (GPR) survey, which enabled for the sedimentary sequences’ chronology to be upscaled for the whole basin and beyond. A prominent peat layer (presumably of Allerød age) has been suggested as a marking horizon to correlate with the Late Glacial lacustrine dynamics in the area. Laminated silt with low organic matter content (of the Younger Dryas age), underlain by sandy silt deposits were discovered both from the boreholes and via the geophysical survey. The lower surface of these strata forms wavy and hummocky bottom relief. Organic muds (accumulated in the Holocene) cover the mineral deposits equally.

UV-Vis spectrophotometric determination of rare earth elements (REE) speciation at near-neutral to alkaline pH. Part I: m-cresol purple properties from 25-75 °C and Er hydrolysis.

The speciation and mobility of rare earth elements (REE) strongly depends on pH, which controls the formation of charged aqueous hydroxyl species. The latter potentially play an important role in controlling heavy REE adsorption on clay minerals in near-neutral to alkaline waters such as in regolith-hosted REE mineral deposits. However, accurate REE hydrolysis constants are needed for developing geochemical models that can predict the role of these charged species in natural systems. Here, we develop a robust experimental UV-Vis spectrophotometric method using m-cresol purple to determine in situ pH from 25 to 75 °C. This method is used to derive the average ligand number and hydrolysis constants of erbium (Er) at 25 °C in aqueous solutions with low ionic strength (≤0.001 mol L-1) at pH from ∼7 to 9.5 and in the presence of Er concentrations from 0 to 0.057 mM. The average ligand number ranges between 1 and 3 indicating that Er(OH)2+, Er(OH)2+ and Er(OH)03 control speciation in the experiments. The logarithm of the Er hydrolysis constants (, n = 1 to 3) derived at infinite dilution for the reaction Er3+ + nH2O = Er(OH)n3-n + nH+ are: , , . Implementation of these experimental data into a geochemical model indicates that the Er(OH)2+ and Er(OH)03 species are both stable in a much wider pH range than previously predicted. Consequently, the positively charged REE hydroxyl complexes can potentially control the fractionation of light vs. heavy REE via adsorption as observed in the formation of certain regolith-hosted REE deposits.