GTF: A New Interpretable Graph Neural Network for Geochemical Anomaly Detection in Mineral Prospectivity Mapping
摘要
Mineral prospectivity mapping plays a critical role in guiding mineral exploration. However, existing data-driven approaches often overlook the spatial dependencies between sampling points and suffer from limited interpretability. To this end, this paper proposes a novel mineral prospectivity mapping method based on an interpretable graph transformer neural network, termed graph transformer (GTF). Compared to graph attention networks, the GTF method effectively captures the informational relationships between sample points across both global and local regions, leading to improved predictive accuracy. Moreover, a gradient descent algorithm is introduced to search for globally and locally optimal subgraphs, enabling the computation of unique contributions from global and local samples. Taking the Changba mineralization area located in Gansu Province, China, as an example, this study evaluated the validity and interpretability of the GTF approach in mineral prospectivity prediction by utilizing 16 mineralization-controlling factors derived from geochemical datasets. The results demonstrate that prospectivity maps generated by the GTF model not only leverage spatial relationships between samples effectively but also analyze the contributions of different features and spatial relationships among samples, considerably improving the precision of delineating potential Pb–Zn mineralization zones.