Unveiling geological complexity in the Serra Dourada Granite using self-organizing maps and hierarchical clustering: Insights for REE prospectingin the Goiás Tin Province, Brasília Belt, Central Brazil

Journal of the Geological Survey of Brazil

Endereço:
SBN Quadra 2 Bloco H - 1° andar - Asa Norte
Brasília / DF
70040-904
Site: https://jgsb.sgb.gov.br/index.php/journal/index
Telefone: (61) 2108-8400
ISSN: 2595-1939
Editor Chefe: Evandro Luiz Klein
Início Publicação: 15/05/2018
Periodicidade: Quadrimestral
Área de Estudo: Multidisciplinar, Área de Estudo: Multidisciplinar

Unveiling geological complexity in the Serra Dourada Granite using self-organizing maps and hierarchical clustering: Insights for REE prospectingin the Goiás Tin Province, Brasília Belt, Central Brazil

Ano: 2025 | Volume: 8 | Número: 1
Autores: G. F. Silva, M. V. Ferreira, L. T. Chemale, I. V. Santana, N. F. Botelho
Autor Correspondente: G. F. Silva | [email protected]

Palavras-chave: unsupervised segmentation, compositional data analysis, clustering algorithms, machine learning, dimensionality reduction

Resumos Cadastrados

Resumo Inglês:

This study explores the use of Self-organizing maps (SOM) combined with hierarchical clustering to provide insights into the geological differentiation and mineral prospecting in the Serra Dourada Granite (SDG), part of the Goiás Tin Province, northern Brasília Belt. After some issues on the geolo-gical cartography of the SDG based on traditional approaches, such as the interpretation of outcrops and the limited geochemistry data, often struggle to capture the complexity of high-dimensional geo-physical datasets. To address this, we apply unsupervised machine learning techniques to segment air-borne radiometric data, providing a more nuanced understanding of the SDG internal structure. Using airborne gamma-ray data, we employed SOM for dimensionality reduction and data segmentation, su-pported by hierarchical clustering. This methodology enabled us to identify distinct geological units with greater accuracy and resolution than traditional methods such as Principal Component Analysis (PCA).The SOM-based approach retained the data's original topology and revealed fine-scale patterns wi-thin the dataset, distinguishing between areas affected by magmatic processes and those influenced by post-magmatic hydrothermalism and supergene leaching. The results indicate that some clusters are mainly associated with magmatic differentiation, characterized by average concentrations of potas-sium (K), equivalent thorium (eTh), and equivalent uranium (eU) and others show evidence of secon-dary processes, including hydrothermal alteration and weathering. Notably, Cluster 4 is spatially linkedto REE-enriched plateaus and the Serra Verde Mine, reinforcing its significance for mineral exploration. The SOM model proved more effective than PCA at capturing non-linear relationships within the data. While PCA provided insights into the primary variance, it did not fully account for the complex geologi-cal processes at play. In contrast, the SOM model segmented the data into clusters that reflected both broad radiometric trends and localized variations, particularly in areas influenced by hydrothermalism and supergene processes. Our findings underscore the value of machine learning techniques, parti-cularly SOM, in geoscientific data analysis. This approach provides a robust framework for integrating multivariate radiometric data, offering valuable insights for geological mapping and mineral exploration, especially in regions with complex geological histories. The methodology presented here can be adap-ted to other geological settings, enhancing the accuracy of subsurface mapping and identifying areas of economic interest, such as Rare Earth Element (REE) and other critical mineral deposits.