Distribuição Geoquímica de Elementos Terras Raras no Morro dos Seis Lagos, Amazônia Brasileira
Distribuição Geoquímica de Elementos Terras Raras no Morro dos Seis Lagos, Amazônia Brasileira
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Palavras-chave: aprendizado de máquina; geoquímica exploratória; minerais criticos; pedometria.
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Keywords: machine learning; exploratory geochemistry; critical minerals; pedometry.
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Abstract: The application of machine learning models to legacy data, remote sensing data, and landscape morphometry has aided in the identification of mineralized zones containing elements with economic potential. Morro dos Seis Lagos contains a thick laterite crust (> 200 m), where the carbonation processes of siderite have produced a goethite/hematite crust, providing a window into the geochemical dynamics of the soil and landscape. The objective of this research was to identify patterns of rare earth element (Ce, Eu, and La) mineralization, especially in hard-to-reach areas. To this end, the Multivariate Adaptive Regression Spline (MARS), Radial Support Vector Machine (SVMRadial), and Random Forest (RF) models were tested to predict the spatial distribution of these elements’ concentrations at Morro dos Seis Lagos. The methodology consisted of using a geochemical legacy dataset comprising 341 samples (soil, sediments, and rock materials) associated with morphometric covariates and spectral indices derived from remote sensing. The results showed that the RF model performed best in predicting the concentrations of Ce (R² = 0.02), Eu (R² = 0.05), and La (R² = 0.21). The Recursive Feature Elimination (RFE) algorithm highlighted the relevance of the following covariates: Elevation, Actual surface area, LS factor, Saga moisture index, Valley floor leveling multiresolution index, Topographic moisture index, and Ferrous iron. Local relief characteristics played a significant role in understanding the spatial variation of the elements, given the greater influence of morphometric covariates, reflecting tectonic control on ETR mobility in areas of lateritic crust and talus.
- Everaldo Zonta
- Niriele Bruno Rodrigues
- Helena Saraiva Koenow Pinheiro
- Waldir Carvalho Junior