From magnetic anomaly to geothermal resource: An updated Curie depth map for the geothermal assessment of Colombia

The study estimates the Curie Point Depth (CPD) of the Colombian territory using magnetic anomaly data and two inversion methods, providing insights into crustal thermal structure. The availability of new magnetic information from the Geological Survey of Colombia and EMAG2V3 satellite data updates the Curie isotherm for northwestern South America. This development represents a significant asset for geothermal energy engineering. The calculation uses the centroid and fractal nonlinear curve adjustment methods, with results compared to tectonic features, ANH geothermal gradients, and element concentrations. The average CPD value was determined to 65.7 km ± 37.8 km (centroid method) and 21.0 ± 9.1 km (nonlinear adjustment method). Following ANH bottom hole temperature data integration, cokriging interpolation refines the nonlinear fractal results and heat flow estimates. This allows direct comparison between three thermal indicators: heat flow derived from CPD centroid calculations, cokriging-based estimates, and direct bottom hole temperature measurements. Shallow CPD values (18–23 km) are observed in the Southern Andes, aligning with high volcanic density and geothermal anomaly areas including Las Animas-Chiles, Cerro Bravo-Cerro Machín, San Diego, and Huila-Sucubun. Deeper values (>30 km) are found in the Northern Andean sector, particularly in the Magdalena Basin, Caldas Tear zone, Bucaramanga's seismic nest, Paipa-Iza regime, and aged geologic bodies. These correlate with the convergence of the Nazca, South American, and Caribbean plates. CPD results show a NE-SW trend controlled by the orogenic system of the three Andean Cordilleras. Moderate correlations exist for calcium (Ca) and potassium (K) in active sediments, but not for iron (Fe), titanium (Ti), and magnesium (Mg).