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Recent discoveries of basement-hosted uranium deposits in the Patterson Lake corridor in the southwestern Athabasca Basin of Canada have brought vigorous exploration interest to the region. New lithostratigraphic constraints, geochronology and airborne geophysical surveys have dramatically improved the understanding of the host basement geology, warranting a re-examination of the remote predictive mapping and geophysical responses of the buried basement rocks. This study took a two-step approach to examine the regional basement geology and architecture. First, a mosaic of the long-wavelength response of potential field (gravity and magnetic) datasets was examined to divide the basement into regional domains based on bulk physical property variations. The interpretive geological model was then refined using textural and lineament analysis of new airborne gravity and magnetic datasets, geological drill hole logs and magnetic susceptibility measurements. The new basement map identifies and updates major features including a crustal-scale structure that separates the southern Tantato Domain from the newly defined eastern Taltson Domain. This structure may have played a role in localizing fluid flow in the Patterson Lake corridor, defining the spatial extents of structurally controlled buried felsic intrusions, and redefines the boundaries of the Taltson, Clearwater and Tantato Domains. In addition, the potential field enhancements delineated significant regional faults that controlled the geometry of Paleoproterozoic cover sequences and have implications for understanding the crustal architecture of the southern Rae Province. These new interpretations shed light on the tectonic history of the region to support on-going exploration activities and delineate regionally prospective areas in this understudied area of the Canadian Shield.Thematic collection: This article is part of the Uranium Fluid Pathways collection available at: https://www.lyellcollection.org/cc/uranium-fluid-pathways

Locating the edges of magnetized sources provides a fundamental tool in the geologic interpretation of magnetic field data. Much recent effort has been expended on developing improvements to existing edge-detection methods, resulting in purported increases in accuracy and continuity along edges, reduction of noise effects, and limiting the influences of variable depth to source, magnetization direction, and source dip. These endeavors are valuable and provide interpreters with a wider range of tools to carry out geologic interpretations of aeromagnetic data. Nevertheless, survey parameters such as flight height and line spacing impose limits on the quality of edge locations that can be achieved. Using model studies, we quantify the effects that source size, depth, and interference between sources have on calculated edge locations. Based on the known behavior of established edge detectors, we found that many of the newer approaches offer limited advantages over older methods. Consequently, we studied an example of field mapping of geologic contacts in the Canadian Shield, supported by aeromagnetic data, using calculation of a standard edge detector: the horizontal gradient magnitude of the total magnetic field or TF-hgm. Calculated edge locations estimated from this method appear sufficiently accurate and continuous to provide a solid basis on which the mapping campaign was based and executed successfully.