Aragonit w utworach czapy wysadu solnego w Rogóźnie koło Łodzi

Abstract

ARAGONITE IN CAP ROCKS OF A SALT DOME AT ROGÓŹNO, NEAR ŁÓDŹ Summary The paper deals with the aragonite having been discovered in the Zechstein cap deposits of a salt dome at Rogóźno, near Łódź. It is the first find of this type in Poland. Aragonite occurs in the topmost part of salt dome cap, in all the main components of the latter, i. e. in clays, clays veined by gypsum, as well as in gypsums and anhydrites. It is most abundant within the upper portions of clays and clays veined by gypsum. Development of aragonite, its forms and site of occurrence point at the exogenetic origin of this mineral, which has been formed after decomposition of gypsum like that occurring at Schaumkalk, in Germany. In the Rogóźno region it makes an additional stratigraphical criterion that allows to determine the upper boundary between deposits of salt dome cap and those being of various age.