Analysis of WorldView-3 satellite imagery for the Andrew Lake area, Alberta

As part of the Alberta Minerals Strategy and Action Plan, the Alberta Energy Regulator / Alberta Geological Survey acquired Maxar WorldView-3 satellite imagery over the Canadian Shield in northeastern Alberta. This acquisition aimed to support the detection and mapping of metallic mineral occurrences, where documented deposits of gold, base metals, uranium, and rare-earth elements are found in narrow belts associated with major shear zones. 
In March 2024, Professor Emeritus Benoit Rivard and Dr. Jilu Feng were contracted to conduct a detailed analysis of WorldView-3 satellite imagery of the Andrew Lake area, building on previous work in the Leland Lakes area. This study, sought to identify mineralization potential by detecting exposed rock outcrops, delineating lithological units, and mapping mineral alteration features within the Alberta Shield. 
This report presents key findings that expand the understanding of the lithological and mineral alteration patterns within the Andrew Lake region. The analysis identified zones with significant internal variability within primary rock units, particularly in the Taltson basement and Rutledge River complexes. These zones revealed high concentrations of minerals such as white mica, biotite, and chlorite. Through the use of a ‘White mica index’ and a ‘White mica / chlorite-biotite index’, previously unidentified areas rich in hydroxyl-bearing minerals were detected. These minerals are present in biotite schists, amphibolite, and garnetiferous layers. This highlights mineralogical diversity that points to potential subunits within the primary mapped units. 
Preprocessing involved masking non-rock features such as vegetation, water, burns, and shadows to refine the detection of rock outcrops. Key spectral indices were applied to analyze iron- and hydroxyl-bearing minerals, facilitating the distinction between mafic and felsic lithologies. Spectral angle mapping (SAM) was used with both image-derived and field-collected endmembers, yielding detailed spectral maps that highlighted zones of potential mineralization and specific lithological contrasts. 
This report’s findings underscore the potential of WorldView-3 imagery for accurately mapping complex lithological features and identifying zones of mineralization, particularly in areas with extensive vegetation cover. Field validation is recommended to confirm remote sensing interpretations and to refine exploration strategies in northeastern Alberta. 
This work was completed under the Mineral Grant provided by the Government of Alberta dated June 22, 2021.