Pyrite-bearing sandstone blocks, western Finland

Sandstone blocks with pyrite cement in the western coastal area of Finland have both concretionary and irregular external forms. In addition to them, a pyrite vein in a sandstone block and also a pyrite-cemented conglomerate with glauconite and phosphorite fragments have been described. Comparisons with some other pyrite concretions have been made and ten new chemical analyses are presented. The source of the blocks is evidently a (Middle-) Cambrian sandstone bed at the bottom of the Bothnian Sea.