Geotectonic setting of Permian polymetallic deposits in the Polish Basin

Abstract

The Pol ish Ba sin is lo cated be tween the Pre cam brian East-Eu ro pean Plat form and the Cadomian Bo he mian and Ma³opolska mas sifs. The base ment of this Perm ian-Me so zoic ba sin com prises mainly Variscides and epi-Cal edo nian Paleo zoic rocks. In the prox i mal (NE) part of the ba sin, the Mid-Pol ish Trough is dis tin guished. In the dis tal (SW) part, the thickness of the Perm ian-Me so zoic suc ces sion is much smaller than in the Pol ish Trough. Palaeorift zones were ac tive from the Perm ian to the end of the Ju ras sic in the dis tal part of this ba sin. The Kupferschiefer min eral sys tem in di cates a palaeorift zone and smaller hot spots as sources of sup ply of met al lif er ous brines. The rel a tively small thick ness of the Rotliegend sand stones and their good per me abil ity and po ros ity prop er ties cre ated very fa vour able routes for the mi gra tion of metal-bear ing brines. The en tire Kupferschiefer polymetallic res er voir is re gion ally sealed by an hyd rites and salts of the Werra cyclothem. This was in clined con stantly from Perm ian times on wards to the north, fa vour ing the mi gra tion of polymetallic brines from rift zones to geo chem i cal res er voir traps. Min eral sys tem anal y sis of the polymetallic Kupferschiefer de pos its shows that the geotectonic set ting of this zone re lates only to the dis tal part of the Pol ish asym met ric rift ba sin. Key words: geotectonics, min eral sys tem con cept, con ti nen tal rift sys tem, Kupferschiefer, polymetallic de pos its, Pol ish Ba sin.