As a result of complex studies - geological-structural, morphostructural analytical, mineralogical mapping of quartz formations, detailed geochemical work and analysis of geochemical fields – forecasting prospecting features of gold ore taxon’s: ore zone; ore field; deposit and ore body. They are characterized by groups of criteria: morphostructural, stratigraphic-lithological, structural-tectonic, magmatic, geophysical, metasomatic, mineralogical, geochemical factors and attributes, and a geological-genetic model of the gold-bearing ore-forming system in the collapse zone. Favorable geological and structural conditions for the localization of gold mineralization in the mountains of Karakchatau are associated with the areas of long-term tectonic-magmatic activation in metalliferous sediments of Є-О contrast lithological composition. The coincidence of manifestations of gold mineralization to the blocks formed by transverse faults at the sites where they intersected the Karakchatau crush zone was noted. To the channel-localizing parts inside are blocky and unextended interblock tectonic structures with positions in favorable “structural traps” in their azimuthal curvatures of executed productive types of hydrothermal, sulfidizing quartz. The results of mineralogical mapping of quartz formations along the Karakchatau crush zone (Western Uzbekistan) are considered. Five genetic types of quartz are distinguished. The most productive of them is hydrothermal quartz of types 3 and 4 associated with pyrite,arsenopyrite and gold, which forms vein fields in areas of kinks and expansion of the zone of crushing. Identification of any goods and services that can be used for commercial purposes, including in the geological structure, other regions of Western Uzbekistan.
This study presents the occurrence of invisible gold and associated trace elements in pyrite from the Late Permian Kővágószőlős Sandstone Formation within the Western Mecsek uranium ore deposit, Hungary. Eight pyrite-rich drill-core samples were analyzed using optical microscopy, EMPA, LA-ICP-MS, and sequential extraction coupled with ICP-OES. Optical microscopy and EMPA analyses identified three pyrite morphologies: framboidal (1–20 μm), cement (50–200 μm), and euhedral (1–20 μm). Framboidal pyrite, of bacterial origin, occurs within organic matter, whereas cement and euhedral pyrites are associated with quartz and feldspar. Cement pyrite occasionally hosts minor sulfosalt and galena inclusions. LA-ICP-MS detected gold in pyrite grains (average 0.33 ppm), while sequential extraction with ICP-OES confirmed gold at 0.42 ppm. Elevated concentrations of As, Zn, and Cu range from 0.2 to 2.3%, along with trace elements such as W (0.05-0.13 ppm), Ba (7- 40 ppm), and Ni (95-244 ppm), were also identified. Gold is interpreted to occur primarily as a solid solution within the pyrite lattice, whereas other trace elements are likely associated with metal nanoparticles on or within the pyrite grains. These findings emphasize the complex geochemistry of pyrite and highlight the necessity for further studies, including sulfur isotope analysis, to elucidate ore-forming processes and gold mineralization mechanisms.
Keywords:
Invisible Gold, Pyrite, Arsenic, Western Mecsek, Uranium Ore Deposit
Geological thin sections and mineral analysis using light microscopy: a comprehensive study
Authors:
Gökhan KÜLEKÇİ
ABSTRACT
This study provides valuable insights into mineralogy and geology by detailing the preparation of geological thin sections and the use of light microscopy for mineral analysis. A total of 120 thin sections were prepared from rock samples collected from different regions, following a structured methodology. The analysis focuses on identifying optical properties that is essential for mineral identification, particularly for quartz, whose distinct color and shape characteristics emerge under polarized light. Recognizing these features can be challenging for experts, making the use of computer-assisted analysis as effective alternative. This study highlights the advantages of Leica polarizing microscopes, which enhance accuracy and efficiency compared to traditional methods. The paper also examines key factors that influence the reliability of mineral identification, addressing the time-consuming nature of conventional approaches. By incorporating digital techniques, researchers can obtain faster, more precise, and reproducible results. Ultimately, this study serves as a comprehensive guide for academics and professionals, offering an in-depth comparison of traditional and modern methodologies in geological thin section preparation and mineralogical studies. The findings contribute to improving mineral identification techniques, ensuring greater accuracy in geological research and applications
Keywords:
Geological Thin Section, Polarizing Microscope, Light Microscopy, Mineral Analysis, Thin Section of Quartz
Gold deposits and mineralization studies: a 2018-2022 Scopus-based bibliometric analysis
Authors:
Svetlana KAMAGUROVA
ABSTRACT
Gold is an important source of economic development and international relations. The accumulation of this element and the formation of deposits is an urgent research problem. The variety of types of deposits, conditions of their formation, and methods of deposit development are of interest to many researchers. Thus, in order to understand the demand for this area, a bibliometric analysis was carried out using the keywords “gold deposits” and “gold mineralization” for a five-year period. The database was acquired from the Scopus and included 793 articles from 77 countries. Statistical analysis was done using the VOSviewer and Mapchart software. Among top publishing countries China, Australia, and Canada took the highest ranks. Top 3 authors stand out as having a high H-index, which indicates their high qualifications in this field. The most popular journal publishing these studies is Ore Geology Review with 259 publications. However, the most cited articles are published in Mineralium Deposita, Economic Geology, Geological Journal, Gondwana Research, Earth-Science Reviews, Geoscience Frontiers, and Geochimica et Cosmochimica Acta. All of these journals are related to Earth and planetary sciences. The large gold mining provinces of China, Australia, and Canada are a key factor in the high publication rate among researchers.
Geochemistry and tectonic signifi cance of the ophiolitic rocks of the Yarpuz-Kaypak (Amanoslar, Osmaniye) area
Authors:
Tamer RIZAOĞLU, Utku BAĞCI, Osman PARLAK
ABSTRACT
Yarpuz-Kaypak (Osmaniye) region, located in Amanos Mountains, contains harzburgitic tectonites and mafic cumulates. The tectonites are represented by serpantinized harzburgites, whereas the cumulates are characterized by gabbronorite and gabbro compositions. The crystallization order within the cumulates is clinopyroxene, orthopyroxene plagioclase and amphibole. The major element compositions of the tectonites and cumulate rocks are consistent with formation in an arc-related tectonic setting. Trace element concentrations of these rocks exhibit large ion litophile element enrichments. Both geochemical and petrographic evidence suggest that the tectonite and cumulate rocks from the Yarpuz-Kaypak (Osmaniye) region represent the remnants of an oceanic lithosphere that formed in a supra-subduction zone tectonic setting during the closure of the Southern Neotethyan ocean and emplaced onto the northern margin of the Arabian platform in Late Cretaceous.
https://doi.org/10.19111/bulletinofmre.501393
Early–middle Miocene reefal limestones are overlain disconformably by late Serravallian– early Tortonian incised valley-fi ll deposits of Dağpazarı formation in the Mut Basin. Dağpazarı formation is composed of mudstone, siltstone, sandstone and conglomerates. Facies associations of the formation are: fl uvial, lagoon, shoal-water delta, shoreface, beach and barrier island deposits. Loxoconcha tumida Brady and Loxoconcha sp. in the gray mudstones indicate the freshwater infl uence and decrease in salinity. Hemicyprideis sp. documents brackish water conditions. The shoreface sandstones alternating with the lagoonal mudstones, and oyster-rich beach deposits in different levels of the sequence indicate episodes of marine connections. The age of the Dağpazarı formation is provided by the planktonic foraminifera from the marine mudstones and marls below and above the formation, and corresponds to the MMi8–MMi10 biostratigraphic interval, which spans the late Serravallian–early Tortonian. Late Serravallian eustatic sea-level fall caused to the quick shallowing of the Mut Basin and subaerial exposure of the reefal limestones at the basin margin. Thus, the incised valley, formed upon the reefal limestones of the Mut formation. This incised valley refl ects a regional forced regression and unconformity. The Dağpazarı formation was deposited within this incised valley following an early Tortonian relative sea-level rise.
https://doi.org/10.19111/bulletinofmre.501543
Relationship between petroleum and iodine in Southeastern Anatolia Basin
Authors:
Adil ÖZDEMİR
ABSTRACT
This study was made for investigating the relationship between iodine and hydrocarbon accumulations and to determine iodine contents of formation waters in the Southeastern Anatolia basin oilfields where have been produced almost all of the Turkey oils (more than 95%). Formation water samples have taken from 234 production wells in 49 oilfields which have different geological structures where oil and gas production has performed by the Turkish Petroleum Company (TPAO). Also, the drilling mud samples from EBY-17 oilwell in Elbeyli (Adıyaman) field has collected, and their iodine analyses were carried out. Although the fields in the Southeastern Anatolia basin are old and some fields the secondary production methods are used, the high relationship between the oil and gas deposits and iodine were proved. As well as in other oil and gas fields in the world, not all reservoir waters in the Southeastern Anatolia basin are saline. However, all of them are rich in iodine. Therefore, the iodine-rich waters are a direct indicator for oil and gas producible reservoirs (containing mature hydrocarbon). Reservoir-targeted iodine geology and hydrogeology methods have simple sampling process, and laboratory analyses can result at a short time. The results are low cost, reliable and consistent. In the case when these data are utilized with other geological and geophysical methods, it is determined will be a practical and useful tool to reduce the hydrocarbon exploration risk to a minimum and to discover new deposits suitable for commercial production.
https://doi.org/10.19111/bulletinofmre.501519
Keywords:
Southeastern Anatolia basin, Iodine, Petroleum hydrogeology, Oil and gas exploration, Oilfi eld waters, Formation waters.
