Phanerozoic veins of galena in the Åland rapakivi area, southwestern Finland

Abstract

Some minor galena mineralizations are in part associated with clastic dykes of Cambrian sandstone in the Aland rapakivi area. Galena also occurs disseminated in greisen-type mineralizations. The difference in age between the two modes of occurrence is probably at least 1100 Ma. No traces of a magmatic source have been found, and hence, a magmatic-hydrothermal origin for the galena associated with sandstone dykes is unlikely. It is suggested that the lead-bearing solutions mobilized from the sediments and precipitated in fissures during compaction and diagenesis.