Editorial for Special Issue “Structure and Origin of Gold Mineralization: From Primary to Placer Gold Deposits”

The high price of gold reached in recent years—exceeding USD 5000/oz in 2026 and expected to continue rising—has generated renewed interest in this precious metal.

The study of the structure and origin of gold deposits is a dynamic area of economic geology, not only because of the strategic importance of gold but also because of the complexity of the processes involved in its formation, redistribution, and concentration.

The main objective of this Special Issue is to adopt a multidisciplinary approach that offers new perspectives by integrating field observations, mineralogical and geochemical analyses, and remote-sensing data for prospective modelling and deposit assessment.

The studies presented in this volume demonstrate that gold research is advancing toward increasingly integrative models, in which structural controls, geochemical fingerprints, geophysical signals, and supergene processes are analysed as parts of a single mineral system.

To achieve this goal, this collection brings together ten contributions, organised in by geographic location and main thematic focus. Some studies focus on geophysical and remote-sensing methods for gold exploration, as well as integrated lithostructural and mineral-potential modelling. Other contributions examine sedimentological and placer-related processes, together with the geochemical and mineralogical characterisation of gold systems. In addition, several studies apply machine learning-based techniques to prospectivity analysis and target modelling. Together, these contributions provide a broad overview of current research on the structure, genesis, redistribution, and exploration of gold deposits in different geological contexts.

Abdelrahman et al. (Contribution 1) explore the use of geophysical methods—specifically magnetic surveying, widely used in the exploration and mapping of precious metals, as well as in the detection of structures capable of hosting mineral deposits—in the Harrat ad-Danun area of Saudi Arabia. This area is characterised by metamorphic and plutonic rocks that form part of the western Arabian Shield and demonstrate the value of aeromagnetic data in delineating structures favourable to Au/Ba mineralisation. The authors identify several favourable aeromagnetic trends and magnetic anomalies associated with faults, shear zones, and subsurface dykes, and conclude that these structural elements directly control the location of mineralisation. The main contribution of this paper is showing that regional tectonic architecture can be accurately reconstructed from potential-field geophysics and, therefore, used as a first-order tool for the exploration of gold deposits.

Modern gold exploration integrates surface and subsurface signals to reduce uncertainty and prioritise exploration targets, as demonstrated by El-Raouf et al. (Contribution 2). They present a methodological workflow for identifying hydrothermal zones and deep structures with potential for gold. The combination of Landsat imagery, topographic data, and the processing of gravity lineaments—on which an oriented principal component analysis (PCA) was performed—allowed for the delineation of alteration areas and the establishment of their relationship with regional structural corridors.

The research of Craw et al. (Contribution 3) utilises the role of unconformities on an extensive regional scale in New Zealand. Based on the analysis of extensive marine unconformities in the South Island of New Zealand, the authors draw analogies to the famous Archean gold-bearing succession of the Witwatersrand Supergroup and examine the importance of transgressive sedimentary settings in concentrating gold in placer-type deposits. This article offers a valuable conceptual reflection on the need to establish analogues among certain gold deposits through sedimentological studies, basin-evolution analyses, and metallogeny, particularly in discussing the origin of paleoplacers and stratabound gold systems.

Australia is a major producer of gold. The integrated study of the central-eastern Yilgarn Craton in Western Australia by Kreuzer et al. (Contribution 4) provides a new lithostructural interpretation using geophysical and remote-sensing tools specifically tailored to the area. The mineral potential modelling workflow used five complementary techniques. Kreuzer et al. (Contribution 4) identified significant spatial relationships between gold mineralisation, gravity ridges and edges, K/Th radiometric anomalies, and certain spectral signatures linked to goethite, clays, and iron. The authors’ integrated strategy can drastically reduce the search space and highlight underexplored areas with high gold potential.

Melchiorre et al. (Contribution 5) incorporate geochemical studies into the investigation of the La Cholla placer gold deposits in Arizona and document how late geothermal fluids can modify pre-existing placers, generating apparently contradictory features. The authors demonstrate that placers should not be interpreted solely as products of mechanical concentration, but also as open systems in which post-depositional chemical processes may operate, reconfiguring the mineralogy and texture of gold.

The Batouri goldfields in eastern Cameroon, South Africa, were studied by Vishiti et al. (Contribution 6). Their research stands out for its combination of soil geochemistry and the microchemistry of particulate gold, and they use both approaches to locate possible source lithologies. The morphological and compositional variability of the gold particles suggests a proximal source in quartz veins hosted by the granitic basement. This article broadens the scope of the Special Issue by connecting gold genesis, regolith exploration, and the impact of artisanal mining activity on the surface geochemical signal.

Li et al. (Contribution 7) analyse the geochemical dimension of the mineralising fluids in the Alin Sb-Au orebodies of the Shuixie metallogenic field in southwestern China. They examined the use of trace and rare-earth elements in auriferous pyrite and the host rock, enabling reconstruction of fluid evolution, and combine an integrated study of mineral microgeochemistry, fluid evolution, and ore formation to provide new insights into this polymetallic gold-bearing deposit.

Shevyrev and Boriskina (Contribution 8) present a k-means machine learning model for Carlin-type gold deposits that enables unsupervised classification of areas of interest using only predictor variables. Their study of such deposits through the analysis of lineaments extracted from remote imagery and digital terrain models, using the pyLEFA software, provides deeper insight into the role of crustal fracture fields in controlling gold concentrations detectable by remote sensing. They demonstrated how combining tectonic information and remote sensing can be used to map the prospectivity of Carlin-type deposits, even in the absence of direct evidence of magmatic sources.

The occurrence of significant gold deposits in Archean conglomerates at Maljavr, in northwestern Russia, adds a particularly relevant temporal and metallogenic dimension. The research by Kalinin et al. (Contribution 9) proposes a complex evolution of gold mineralisation, including an initial stage of metasomatism and a subsequent redistribution of gold associated with the intrusion of a tourmaline-bearing pegmatite. The authors highlight its significance as one of the first recognised examples of gold mineralisation in Archean conglomerates in the Fennoscandian Shield. This study contributes to the volume’s objective by showing that the history of a gold system may be polyphase and that the mineralisation observed today may result from superimposed events of different ages and origins.

Finally, the auriferous quartz-vein deposits of the Eastern Kazakhstan Gold Belt, an important black-shale-hosted gold province, are also noteworthy. Konopelko et al. (Contribution 10) differentiate mineralisation styles and document associations with auriferous sulphides and veins containing visible gold. They demonstrate the value of alteration zones and Au–As–Pb–Sb geochemical associations for regional prospecting.

Overall, the contributions brought together in this Special Issue show that the study of gold mineralisation can no longer be approached from a single perspective and that geological structure continues to play a fundamental role in controlling gold mineralisation. The interpretation of the structural setting becomes more powerful when integrated with other techniques, such as geochemistry, geophysics, remote sensing, spatial modelling, and advanced mineralogical characterisation. This volume confirms that gold deposits result from complex histories of formation, reworking, overprinting, redistribution, and more, and its contributions are at the intersection between origin, structure, exploration, and mineral behaviour.

Thus, this collection may contribute to the detection of new deposits in deep-crustal domains by integrating geological knowledge accumulated in recent years through scientific research applied to mineral exploration. The context of exploration today is one in which a large proportion of the resources cropping out near the Earth’s surface are already known, and thus, future exploration must be directed toward concealed targets hosted in deeper levels of the crust. Exploration will likely be supported by predictive geological models, robust metallogenic criteria, and geophysical, geochemical, and remote-sensing tools, combined with advances in artificial intelligence, to successfully explore deep-crustal levels that are not directly accessible.