3D gravity modelling applied to the exploration of uranium unconformity-related basement hosted deposits: the Contact prospect case study, Kiggavik, NE Thelon region (Nunavut, Canada)

• Main Authors: Roy, Régis, Benedicto, Antonio, Grare, Alexis, Béhaegel, Mickaël, Richard, Yoann, Harrison, Grant
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2017
• Subjects: Canada; Nunavut
• Online Access: http://hdl.handle.net/1807/77678; http://www.nrcresearchpress.com/doi/abs/10.1139/cjes-2016-0225

In unconformity-related uranium deposits mineralization is associated with hydrothermal clay-rich alteration haloes that decrease the density of the host rock. In the Kiggavik Uranium project, located in the eastern Thelon Basin, Nunavut (Canada), basement-hosted shallow deposits were discovered by drilling geophysical anomalies in the 1970s. In 2014, gravity data was inverted for the first time using the Geosoft VOXI Earth ModellingTM system to generate 3D models to assist exploration in Contact, the most recent discovery at Kiggavik. A 3D unconstrained inversion model was calculated before drilling and a model constrained with petrophysical data model was computed after drilling. The unconstrained inversion provided a first approximation of the geometry and depth of a low density body and helped to collar the discovery holes of the Contact mineralization. The constrained inversion was computed using density values measured on 315 core samples collected from the 21 drill-holes completed between 2014 and 2015. The constrained modelling highlights three shallower and smaller low density bodies that match the geological interpretation and refines the footprint of the gravity anomalies in relation to the current understanding of the deposit. The 3D inversion of gravity data is a valuable tool to guide geologists in exploration of shallow basement-hosted uranium deposits associated with alteration haloes and to assess the deposit gravity geometry. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.