Gold prospectivity maps of the Red Lake greenstone belt: application of GIS technology

Abstract

Recent advances in the use of Geographic Information Systems (GIS) software and analysis can be used in conjunction with traditional geoscience data sets to determine effective predictors for gold mineralization, from which mineral prospectivity maps can be generated that highlight potential exploration targets on a regional scale. In this paper, key components of the Archean lode gold deposit model for the Red Lake belt are selected and modeled using weights of evidence (WofE) analysis and logistic regression, leading to the creation of gold prospectivity maps. The best predictors for past and present gold producers in the Red Lake camp, according to WofE analysis include (1) elevated trace elements, Au, As, and Sb; (2) a number of alteration indices calculated from oxide geochemical data; (3) alteration characterized by pervasive and vein-style ferroan carbonate and elevated Au, As, Sb, and S anomalies; (4) proximity to the Mackenzie Island stock and diorite phases of the Dome stock; and, (5) tholeiitic basaltic flows and associated gabbroic rocks of the Balmer assemblage. Gold prospectivity maps produced by logistic regression using binary evidence maps highlight anomalous localities within known and highly prospective areas in the district (Madsen – Red Lake corridor, Balmertown – Cochenour – East Bay). In addition, a number of localities not known to contain significant deposits were also identified as prospective.