O złożowej mineralizacji barytowo-fluorytowej w Jeżowie Sudeckim (Sudety Zachodnie)

Abstract

A BARITE-FLUORITE DEPOSIT IN JEŻÓW SUDECKI (WESTERN SUDETES)SummaryMinor symptoms of barite, fluorite, and sulphide mineralization in the vicinity of Jeżów Sudecki, close to the main Mrid-Sudetic dislocation, had already been mentioned in earlier literature (H. Traube, 1888; A. Sachs, 1906). In 1969–1973, the present author traced a tectonic zone, partly mineralized with barlite and fluorite, which is parallel to the main Mid-Sudetic dislocation. This zone, described as the Jeżów Sudecki Fault, is situated within the metamorphic massif of the Góry Kaczawskie (Figs. 1, 2). In addition to this, a similarly developed, parallel fault zone, was traced in boreholes about 40 m to the south. However, the latter zone is only slightly mineralized.The rock series of the metamorphic massif of the Góry Kaczawskie run in an east-west direction and dip northward at an angle of 60° to 70°. They consist of green schists, sericite-chlorite schists, locally with graphite, quartz-albite schists, and crystalline limestones. These rock series are assigned by H. Teisseyre (1956, 1967) to the Pilchowice unit, but in lithology they resemble more closely the rocks series of the Bolków and Świerzawa unit (M. Szalamacha, 1971).The Jeżów Sudecki Fault was investigated at a length of about 1800 m. It is characterized by four segments differing in the degree of minera1ization. The richest segment of the Fault, and the one which has been studied in most detail, is mineralized with barite and fluorite; it is situated on the south-eastern slope of the Szybowisko Hill. In this part of the fault, the author traced a barite vein which is 210 m long and extends to a depth of 1,50 m. Barite and fluorite, in the form of veins, lenses, and impregnations, penetrate here into the rocks of a tectonic zone which is up to 11 m. wide and dips to the south (Fig. 5). In the eastern part (test pit S-I and borehole WJ-II), the author traced a vein (Fig. 6) which measures – on the average – 11.31 m in thickness; the content of fluorite in this vein ranges from 2.88 to 22.47 per cent and that of barite from 39.84 to 912.46 per cent. The vein occurs among green schists, kataclasites, greenstone micro-breccias, tectonic loams, and – locally – porphyry. Three parallel mineralized zones were distinguished in the second section, in the western part; the content of fluorite in these zones varies from 1.39 to 31.73 per cent and the content of barie ranges from 28.76 to 96.56 per cent.On the southern slopes of a hill (altitude of 541.3 m), the author distinguished a segment of the Jeżów Sudecki Fault, which is about 750 m long and shows symptoms of barite mineralization. A barite vein, measuring 120 m. in length and from 0.5 to 1.0 m in thickness, was traced in the central part of this segment. The remaining parts of this zone are composed of micro-breccias, greenstone kataclasites, and tectonic clays, mineralized with barite, with carbonates in the from of small veins and concentrations. Barite mineralization was also observed in another, southern fault in the same area.The microscopic picture shows the occurrence of barite, fluorite, lead sulphides, zinc sulphides, copper sulphides, quartz, calcite, dolomite, strongly disintegrated ankerite, and celestine. On the basis of different type's of mineral par1agenesis distinguished in the particular sections, the author assumes that just as in the deposit near Stanisławów (J. Jerzmański, J. Kornaś, 1970; A. Piaulo, 1972) the following types of mineral paragenesis occur in the area described here: quartz-barite-fluorite-lead sulphides, zinc sulphides, copper sulphides quartz-barite-fluorite-haematite quartz-barite-fluorite-lead sulphides, zinc sulphides, copper sulphides carbonates (Ca, Mg, Fe)-quartz-haematite-bariteIn its paragenesis, form, and connection with the Mid-Sudetic Fault, this mineralization is distinctly related to already known barite deposits in the vicinity of Boguszów, Jabłów, Głuszyca, and Jedlina. The linear arrangement of the zones of barite mlineralization along, the main Sudetic dislocations (Mid-Sudetic Fault, Leszczyna-Stanilsławów Fault, Harrachov – Jakuszyce Fault), independently of older geological structures, leads to the conclusion that they all represent a single group of deposits, which is connected with the young or rejuvenated tectonics of regional dislocations. The age of these dislocations is certainly post-Variscan and probably extends to the Trias or the Cretaceous. This would correspond to the stage of tectonic-magmatic activity along Sudetic dislocations during the platform period of the folded Caledonian-Variscan geolsyncline.