Uwagi o genezie złóż kruszcowych w północno-wschodniej części Gór Kaczawskich

Abstract

REMARKS ON GENESIS OF ORE DEPOSITS IN THE NORTH-EASTERN PART OF THE KACZAWSKIE MTS.SummaryBasing on the new and hitherto unknown evidences, the present author tries to explain the genesis of the ore deposits (Fe, Pb, Zn, Cu) occurring in the north-eastern part of the Kaczawskie Mts. (Chełmiec, Męcinka, Stanisławów). These deposits are known from mine activity since XVI c. At present, however, only a barite deposit is exploited there, at Stanisławów (J. Jerzmański, 1957). So far, the deposits in study were thought to be of magmatic-hydrothermal origin (W. E. Petrascheck, 1933, 1937; A. Neuhaus 1936a, 1936b, and others) and, as a rule, were referred to the activity of granite magma of the Karkonosze Mts. The author analyses the geological structure of the occurrence area of the deposits and discuses the old Palaeozoic volcanic complex more in detail. Due to numerous drillings it was possible to ascertain that the individual varieties of the volcanic rocks (chlorite schists, epidote schists, diabases, keratophyres) genetically constitute a uniform spilite-keratophyre formation. The thickness of this volcanic complex is thought to be approximately 300 - 500 m. The complex rests at the top of mica schists of upper Ordovician (?) age and embraces a considerable part of the Silurian, probably also the lower members of the Devonian. The ore deposits here considered are genetically and spatially connected with the spilite-keratophyre formation discussed above. The deposits bear traces of albitization, kaolinitization, pyritization (propylitization), silicification, carbonatization and hematitization processes. In conclusion, the author is of the opinion that the ore deposits occurring in the north-eastern part of the Kaczawskie Mts. should be reckoned, according to H. Schneiderhöhn (1962) as sub-marine, exhalation-sedimentary, or, according to W. I. Smirnov (1964, 1965), as volcanic-sedimentary, or subvolcanic-exhalation hydrothermal ones. The deposits in study cannot show any connection with granite intrusions (Karkonosze, Strzegom - Sobótka), since they are older than these latter. On the other hand, as shown by the author, tectonical factors (Young-Caledonian (?) and Early-Variscan phases) and later hypergene processes greatly influenced the final development of the deposits under consideration.