The legacy Mount Morgan mine in Central Queensland, Australia, presents both an environmental challenge and an opportunity for mineral resource development through the reprocessing of historical mine waste and tailings. For over 100 years, the Mount Morgan gold- and copper-bearing ore body was one of the richest in the world. This study integrates satellite, drone-based, and ground truth data to characterise the composition and degree of weathering of mine-derived materials, with a particular focus on their implications for environmental management and mineral characterisation.

Several scenes of high-resolution WorldView-3 multispectral imagery were reprocessed to provide synoptic coverage of the mine site and to identify spectral indicators of temporal changes across waste dumps and tailings storage facilities. To complement this, as part of the EU-funded M4Mining project development (www.m4mining.eu; Horizon Europe scheme), drone-based hyperspectral imagery was acquired using a Mjolnir VS-620 sensor operating across the Visible to Near- and Shortwave Infrared (VNIR-SWIR), with a combined wavelength range of 400-2500 nm, in May 2025. Here, the drone-based hyperspectral data are displayed as 3D surfaces using co-acquired LiDAR data. The drone hyperspectral dataset offers very high spatial and spectral resolution, enabling the discrimination of fine-scale mineralogical and compositional variations that are not resolvable from satellite data alone.

Thirty-six control points were marked for spectral sampling using a portable field spectrometer for ground validation of the drone data. A subset had physical samples collected for bulk geochemical analysis. This integration of multi-scale spectral data and ground truthing provides robust validation of the spectral interpretations and enhances confidence in mineral mapping outputs. Preliminary results reveal a high degree of weathering within the mine waste, with spectral signatures of iron oxides, sulphates, and clays associated with oxidative weathering and acid-generating processes. The approach allows high-resolution spatial characterisation and insights into how different parts of the mine waste and tailings deposits are evolving in 3D.

The work is particularly timely as Heritage Minerals, the current site owners, are evaluating the economic potential of reprocessing the tailings for gold and copper recovery. The results provide a framework for assessing both environmental risks and re-mining potential, highlighting the dual role of advanced remote sensing technologies in supporting sustainable mine rehabilitation and resource recovery strategies.