Journal of the Geological Survey of Brazil

Gender inclusivity in artisanal and small-scale tanzanite mining in Mererani Demarcated Area, Tanzania: A future perspective

Michael Msabi — 2025-08-21

This study examines the impact of Tanzania’s 2017 regulatory and institutional reforms on artisanal and small-scale mining (ASM) operations, with a focus on women’s participation in the tanzanite production value chain. Using a longitudinal research design and descriptive analysis of secondary data from the resident mine office, the study highlights significant growth in ASM activities in the Mererani area. In 2023, the ASM operators and other actors in the study area totalled 45,385 people, with men comprising 35,095 (77.33%) and women comprising 10,290 (22.67%). This indicates a substantial increase from the 4,210 people (3,231 (76.7%) men, and 979 (23.3%) women) recorded in 2018. Notably, the number of women holding mining licenses grew from 10 to 100, while female mine workers increased from 100 to 600 during the same period. Despite these advancements, men continue to dominate license-holding, although the gender gap has narrowed, indicating progress toward gender inclusion. The study also reveals a gradual expansion in tanzanite trading, with a rising number of license holders between 2018 and 2023. To further enhance women’s involvement, the paper advocates for a multifaceted approach, including targeted financial and technical support, establishment of cooperative unions, capacity building in value addition, and the creation of a more conducive operational environment. These measures are crucial for promoting equitable and inclusive economic growth in the Mererani area. The findings underscore the importance of sustained efforts to support ASM operations and promote gender equality in Tanzania’s tanzanite mining sub-sector, which remains a vital contributor to the national economy.

A scientometric study on Artificial Intelligence for landslide prediction: Trends, collaborations, and advances

Mallikarjun Kappi — 2025-11-06

This scientometric study analysed 1,834 publications (2009–2023) on artificial intelligence applications in landslide prediction, revealing rapid growth (26.66% annual citation rate) with an average of 45.80 citations per paper. Despite the increased number of publications, the citation impact has not increased proportionally. The top 25 authors contributed 50.87% of the total output, while international collaborations (42.42% of papers) drove progress, with China and Vietnam as key contributors. Funded research (1,307 papers) generated 59,863 citations. Geology dominated the discipline, although agriculture achieved the highest citation impact. Q1 journals (e.g. Catena and Landslides) outperformed Q2 venues (e.g. Remote sensing) in terms of citations. Among the 227 highly cited papers (12.38% of the total), the average citation count was 215.1. The core themes included machine learning, landslide susceptibility, and deep learning. The findings highlight AI’s multidisciplinary potential of AI but underscore the need for enhanced international collaboration, explainable AI for model transparency, and strategies to mitigate citation biases to maximise research impact.

Gold particle chemistry and vein architecture in the Serrita–Salgueiro District, Western Transversal Zone of the Borborema Province, Brazil

Stella Bijos Guimarães — 2025-12-02

Gold occurrences are distributed across the Serrita-Salgueiro District in the western part of the Transversal Zone, Borborema Province, Brazil. The host rocks are sulfide quartz veins in metasedimentary rocks attributed to the Salgueiro Complex and quartz-monzodiorites, granodiorites, and tonalites of the Serrita Suite. The Au-Ag-(As) and Au-Pb-(Cu) mineralizations in the Salgueiro and Serrita areas of the Salgueiro-Serrita District are hosted in quartz veins arranged in fractures and faults of extensional systems, sheeted veins, and hydrothermal breccias, which range from 0.1 to 1.5 meters in thickness. These veins are vertical to sub-vertical and oriented in an east-west (E-W), northeast-southwest (NE-SW), and north-northwest-southeast (NNW-SSE) direction. In the Salgueiro area, free gold is included in pyrite, chalcopyrite, arsenopyrite, hematite, and martite. In contrast, in the Serrita area, gold occurs alongside pyrite, chalcopyrite, and centimetric galena. Gold particles from the Salgueiro area exhibit Au contents ranging from 44 to 92.5 wt%. Au and 6.8 to 51.5 wt% of Ag. In Serrita, the Au content ranges from 74.4 to 94.7 wt%, and the Ag content ranges from 6 to 22 wt%. The fineness of Au varies from 770 to 930 (with an average of 875) in the Serrita area, and in Salgueiro, it ranges from 461 to 930, with an average value of 707. The chemical variations and hydrothermal halos next to granitic associations favor the contribution of magmatic-hydrothermal fluids. However, major shear zones close to deposits, chlorite-carbonate halos in metasediments, favor orogenic gold deposits at shallower emplacement. Recognizing hybrid fluid sources such as magmatic and metamorphic hydrothermal could enhance the understanding of gold deposition, which has implications for exploration strategies in similar geological settings.

VisualEasier - An enhanced visualization tool for mineral chemistry data analysis

Lucas Mesquita — 2025-10-15

VisualEasier is a user-friendly application designed to improve the visualization and interpretation of spatially resolved geochemical data. Developed in R environment with the Shiny package, it provides a dynamic interface that allows users, regardless of programming experience, to generate high-resolution elemental maps, apply image filters, and perform clustering analysis. The application supports datasets from varied analytical techniques, such as SEM-EDS, Electron Microprobe, Micro-XRF, and LA-ICP-MS, as long as the input is as comma-separated values with pixel-level positional reference. Users can produce elemental maps with pixel-by-pixel normalization, generate ternary RGB compositions to explore elemental associations, and apply median or gradient filters to enhance visual features such as grain boundaries or reduce noise. The clustering module uses the k-means algorithm to organize the sample into user-defined compositional groups, returning a set of outputs that includes spatial maps, statistical tables, and boxplots for each cluster. All graphical findings can be imported as high-quality vectorized PDF files. The system’s flexibility allows users to input normalization references, color palettes, and visualization scales. Application on real samples demonstrated the effectiveness of the application in uncovering compositional patterns that are not easily identifiable using conventional static plots. The clustering results provided insights into mineralogical domains and potential zoning within the sample, while the filter tools improved the clarity of textural and chemical boundaries. The combination of interactive features, compatibility with multiple data sources, and customizable outputs makes VisualEasier a versatile tool for geologists, mineralogists, and materials scientists looking to improve data interpretation. The application is particularly valuable in exploratory and research environments where rapid feedback and visual diagnostics play a critical role in decision-making and hypothesis generation.

Inventory of geological samples collected from the Rio Grande Rise: Caeté Lithotheque (Minas Gerais State), Geological Survey of Brazil

Edgar Romeo Herrera de Figueiredo Iza — 2025-11-19

The Rio Grande Rise Project (PROERG), developed by the Geological Survey of Brazil since 2009, has collected hundreds of cobalt-rich ferromanganese crusts, sediment samples, and biological material. After 14 years of storage, a systematic inventory was carried out between October 2024 and August 2025 at the Caeté Lithotheque, in the state of Minas Gerais. The work included classification, reorganization, and documentation of lithotypes, thin sections, and geochemical aliquots. A total of 132 stations were inventoried, corresponding to 13.6 t of samples, including 355 geochemical aliquots, 114 new aliquots, 57 thin sections, 4 piston cores (129 m), and 1659 photographs. The results highlight the scientific and strategic importance of the collection for cobalt- and phosphate-rich crusts, paleoceanographic reconstruction, and fossil occurrences. Recommendations include more detailed studies of ferromanganese crusts, thin section production, generation of geochemical data, research on stromatolites, and fossil specimens, including a probable Otodus megalodon. The revitalized PROERG collection represents a significant contribution to marine geology, sovereignty over marine resources, and the dissemination of geoscientific knowledge.