Górnojurajskie dolomity z okolicy Hedwiżyna (płd. Lubelszczyzna)

Abstract

UPPER JURASSIC DOLOMITES FROM THE VICINITIES OF HEDWIŻYN (SOUTHERN LUBLIN REGION) Summary Macro- and microscopic studies showed late diagenetic origin of Upper Juras.sic dolomites from the vicinities of Hedwiżyn (SE Poland). In that area, dolomitization affected oolites and pelolites originating at the boundary of shoal and somewhat deeper lagoon. This process presumably took place after the stylolitization stage, in time coinciding with the peak in development of evaporitic lagoon in south-eastern Poland (Kimmeridgian). According to chemical and geochemical data, this process was due to action of brines originating in nearshore zones and subsequently percolating into lithified limestone rocks ("reflux" model). The degree of dolomitization is found to decrease along with increase in depth.