Kalcyty w utworach krasowych rejonu częstochowskiego

Abstract

CALCITES IN KARST FORMATIONS IN THE CZĘSTOCHOWA REGIONSummaryThe article presents a detailed history of calcite exploitation in the Częstochowa region, ranging from 1900 to 1958. Discussed are sites of previous exploitation (Figs. 1 and 2), mode of extraction, and application of calcite.The calcites occur here in the Upper Jurassic formations, i.e. in rocky and platy limestones, at some points within the area between Częstochowa and Kroczyce. It has been ascertained that the calcite is developed here in several varieties: layered calcite, columnal calcite and sinter calcite. The layered calcite occurs mainly in the form of nests of various size. The columnal calcite is found predominantly in veins and fissures. At the walls and roofs of voids and caves occur sinter calcite, as well as beautifully developed stalactites and stalagmites. Shapely calcite druses or fine single crystals are also frequently found in cavities (Tables II, III).Microscope examination was a basis to distinguish calcites, white, cream-yellow, milky, and honey-yellow in colour, or entirely transparent (Table IV). As rule they are hard and compact, even when porous and fractured. Examinations of thin slides have demonstrated that these are mainly coarse-grained, allotriomorphic calcites, at places prismatic and fibrous, in one case also monocrystalline. Frequently, they are enriched in clay substance. At places there are found coatings, of iron hydroxides, locally with fragments of fauna.The calcites under discussion are characterized by a great uniformity chemical composition, particularly by a very uniform CaO content (more than 55%), this giving, after conversion, more than 98% CaCO3. The reachest in carbonates are calcites found in the Vicinity of Olsztyn, Okrąglik and Julianka.The Częstochowa calcites might be used in glass, optical, chemical and building industries, but on account of rather small reserves and due to the fact that they occur in a nature protection area, they will be not exploited.