Minerały autigeniczne i osady w strefie hyporeicznej aluwiów Białej Przemszy zanieczyszczonej przez górnictwo rud metali

Abstract

Authigenic minerals and sediments in the hyporheic zone of the Biała Przemsza River polluted by metal ore mining.A b s t r a c t. Sediments and waters of the hyporheic zone have been investigated in the middle reach of the Biała Przemsza River (southern Poland). The river is polluted with mine waters discharged from lead-zinc ore mines, and ground waters sampled from piezometers in a sand bar are polluted to a similar degree down to a depth of at least 3 m. Very high content of heavy metals in the upper 1 m-thick strata of the bar indicates that their accumulation follows start-up of the lead-zinc mining in the mid-20th century. Common authigenic pyrite, gypsum and other less widespread heavy metal minerals are observed in the sediments of both the mining- and pre-mining times. It is related to the intense infiltration of sulphate-rich waters into the sand bar and microbially controlled anoxic conditions, which favour pyrite formation.