Fuzzy logic spatial modelling as targeting tool for orogenic gold mineralization in the Central Lapland greenstone belt, Northern Fennoscandian Shield, using high-resolution multi-element airborne geophysical data

Very high-resolution detailed airborne surveys, using 50 m line spacing, were
conducted in 2004 over a 260 km2 area in the central part of the Central Lapland
greenstone belt (CLGB) of northern Finland. Multiple sensors onboard the aircraft
acquired magnetic, electromagnetic, and gamma-ray spectrometry data. Together
these data give attributes for interpreting the structures, alteration zones and lithologies
in the underlying bedrock that may be related to orogenic-mesothermal gold
mineralization. To locate prospective targets within the CLGB, the airborne geophysical
data were combined with regional gravity data and regional till geochemistry
using a GIS-based fuzzy logic overlay method. The resulting gold mineralization
potential (“prospectivity”) map defines several areas where alteration zones coincide
with favorable structural targets, providing a guide for future exploration.