Spatial analysis of mineral deposit distribution: A review of methods and implications for structural controls on iron oxide-copper-gold mineralization in Carajas, Brazil

摘要

Mineral deposits are formed by interaction of various geological processes and conditioned by controls that favor their formation and preservation. The understanding of mineralization controls is critical for mineral exploration because it allows focusing exploration on regions where these controls are concentrated. The analysis of the spatial distribution of mineral deposits, particularly on a regional scale, can provide information relevant to the understanding of regional-scale processes involved during their formation. Here we present a review of Fry and fractal methods for spatial analysis of mineral deposit distribution and an application using the iron oxide-copper -gold (IOCG) deposits of the Carajas Mineral Province (Brazil). Results show that different IOCG mineralization structural controls acted in scales of <10-15 km, 15 to 40 km, and >40 km. The IOCG deposits cluster at scales of <40 km, whereas different clusters of IOCG deposits form WNW-ESE alignments at scales larger than 40 km. Structures oriented to WNW-ESE, E-W and NW-SE,with secondary trends to ENE-WSW and NNE-SSW, host the main IOCG deposits in Carajas. Additionally, Carajas IOCG deposits are located in areas with intermediate to high fractal dimensions, reflecting tracts with intermediate to high complexity of structural patterns. Information yielded in this work provides relevant criteria for further exploration for IOCG deposits in the region, including an indication of a possible new WNW-ESE central trend, apart from the northern and southern copper belts in the Carajas Mineral Province. (C) 2016 Elsevier B.V. All rights reserved.