Application of modern 2-D and 3-D seismic-reflection techniques for uranium exploration in the Athabasca BasinThis article is one of a series of papers published in this Special Issue on the themeLithoprobe — parameters, processes, and the evolution of a continent.

Abstract

Seismic-reflection techniques have been applied in several studies over the last 20 years as a uranium-exploration tool within the Athabasca Basin and have been utilized to provide the larger structural context for known uranium deposits within the basin. At the crustal scale, deposits within the eastern Athabasca Basin are shown to be associated with deep-seated shear zones that originated during Trans-Hudson orogeny and have subsequently been reactivated during and subsequent to deposition of the basin-fill sandstones. Seismic properties of the Athabasca sandstones and underlying basement have been determined through in situ borehole measurements. Reflectivity within the sandstones is generally weak. Seismically recognizable signatures are primarily associated with variations in fracture density, porosity, and degree of silicification. The basement unconformity and regolith, a prime target of exploration, is widely imaged as it is characterized by variable but generally distinct reflectivity. Results from the McArthur River mine site suggest that the spatial coincidence of seismically imaged high-velocity zones and deep-seated faults that offset the unconformity may be a more broadly applicable exploration targeting tool. Three-dimensional (3-D) seismic imaging near existing ore zones can define the local structural controls on the mineralization and point the way to new targets, thus leading to more efficient exploration drilling programs. Furthermore, seismically generated structural maps of the unconformity and rock competence properties may play a significant role at the outset of mine planning.

Tectono-metamorphic evolution of the pre-Athabasca basement within the Wollaston–Mudjatik Transition Zone, Saskatchewan

“…Annesley and Madore (1994) observed that the Wollaston-Mudjatik boundary, in the Wollaston Lake area, marks an abrupt change of lithology and structural style. However, to the southwest, Annesley et al (2005, and references therein), Gyorfi et al (2007), Hajnal et al (2010), among others, showed that this domain boundary is a highly heterogeneous transition zone both across and along strike.…”

“…1), during the EX-TECH IV project (Hajnal et al 2010). This reflector below the Athabasca unconformity is referred to as the "Dipping Reflector" (DR) in Hajnal et al (2007).…”

Seismic methods in mineral exploration and mine planning: A general overview of past and present case histories and a look into the future

“…Seismic methods are well-suited to exploration in this setting as the uranium deposits typically occur near the unconformity that separates an undeformed clastic sequence from underlying metamorphic crystalline basement rocks. As summarized by Hajnal et al (2010), the first successful demonstration of high-resolution seismic methods during the Lithoprobe project spawned several subsequent 2D exploration surveys at Shea Creek in 1997, McArthur River in 2004 (e.g., Gyorfi et al, 2007;, Russell and Moore Lake in , and Midwest Northeast and Millennium 3D surveys in 2007(e.g., Juhojuntti et al, 2012Wood et al, 2012). Hathor Resources performed the first seismic-based major uranium discovery in 2007, leading to a 2010 total resource of 12.1 million pounds of U 3 O 8 .…”

EON-ROSE and the Canadian Cordillera Array – Building Bridges to Span Earth System Science in Canada

“…Sudbury impact structure, Creighton 402 Orebody; Eaton et al 2010), uranium deposits (e.g. Athabasca Basin, McArthur River Mine;Hajnal et al 2010), and diamondiferous kimberlites (e.g. Diavik, A154 pipe; Snyder and Grütter 2010).…”