Lead-zinc ores dependent on cyclic sedimentation

Lagoonal sediments of the upper part of the Wetterstein-limestone (Ladinian/Carnian, Alpine Triassic) of the lead-zinc deposit of Bleiberg-Kreuth were examined. They are influenced by cyclic successions, which show emersion periods. These emersions can also be found in similar rocks of the same age. The cyclothems are attributed to eustatic fluctuations. In the rocks, underlying the unconformity, karstic cavities were formed. The lead-zinc ores are thought to be mainly intra-karstic sediments, detrital and chemical deposits. The metal-concentration in the cavities seems to have originated from a directly preceding enrichment in the evaporitic phase, as well as from the erosion of this and other neighboured sediments.