On the possible modes of origin of the Caledonian sulfide ore deposit at Bleikvassli, Nordland, Norway

Lenticular ore bodies of massive sulfide (pyrite, sphalerite, galena) lie along a zone that has schistose metasedimentary wall rock at the southern end of the deposit, and relatively massive microcline gneiss. The ore lenses are generally concordant with banding and foliation, but local discordance and truncated folds indicate that this concordance may be largely tectonic. The ores have clearly been deformed and metamorphosed since their emplacement. 'The geological picture is amenable to explanation by either (a) premetamorphic (syngenetic or diagenetic) emplacement of the sulfides, or (b) syntectonic epigenetic emplacement' along a preexisting shear zone.

This record provided courtesy of AGI/GeoRef.