Gold exploration using till at Petajalehto, northern Finland

摘要

Till geochemistry, ground geophysics, heavy mineral studies anddiamond drilling have been used for gold exploration at the Petajalehto target,northern Finland. Geochemical anomalies of gold and its pathfinders Cu, Bi, Co andTe in detailed till sampling have encouraged further exploration at the target scale. Inaddition, tens of Au nuggets in heavy mineral concentrates of basal till and inpre-Quaternary regolith indicate significant Au mineralization in the target area.Preliminary lithological studies based on the outcrop observations and drill-coresproved the hydrothermally altered, brecciated shear zones in granite gneiss andamphibolite host rocks to be suitable for Au mineralization. The source for Aunuggets seems to be the quartz–carbonate and magnetite–pyrite–quartz veins. Thisresearch also strengthens the concept of effectiveness of surficial geological methodsfor tracing potential sources of mineralized debris and rock fragments in glaciatedterrains.