Boros István (szerk.): A Magyar Természettudományi Múzeum évkönyve 51. (Budapest 1959)

Kaszanitzky, F.: Genetic relation of ore occurrence in the Western Mátra Mountains, North Eastern Hungary

tion between the veins and between parts of one and the same vein. The disclosures have revealed that there exist differences of age between the vein system of different strike. The Arany Péter vein of north-north-easterly strike is displaced by the Aranybányabérc and Péter-Pál veins of approximately northerly strike. Therefore the precedence of the Arany Péter is indubitable. The microscopic investigation of the mineral association has corroborated this evidence. Sphalerite and galena predominating in the ore of the Aranybányabérc vein are identical with the young galena and sphalerite of the Arany Péter vein. The strike of the Bányabérc and Malombérc veins is the same as that of the Arany Péter. The surface outcrop of the Bányabérc vein, in the norther part of the area, is 750—800 metres above sea level. The main gallery has traversed the same on the 450 metre level. On the other hand, the outcrops of the rest of the studied veins are situated at about 350 to 500 metres. It is therefore evident that the association of the disclosed and investigated parts of the Bányabérc vein cannot be correlared with the main-gallery level section of the Arany Péter vein. In the Bányabérc vein older galena and sphalerite is predominating. Wurtzite is absent. The mineral association parallels that of the —200 metre level of the Károly vein. The disclosed part of the Malombérc vein, situated some 900 metres south of the Arany Péter vein, is very near the surface (25—30 metres). As was mentioned, the southern part of the ore body was significantly displaced in the downward sense along the great fault occurring in the area of the Károly shaft. In our opinion, the Malombérc vein carries workable ore only beneath the —150 metre level. The optimum workability of the rest of the veins occurs around the main gallery level or below. The Károly vein is considered at present to be workable in a vertical extension of 300 metres on the average. Of this extension, 100 metres fall above the main gallery level. According to the vein structure and mineral association of the veins on the —200 metre level, workable quantities of ore are to be expected in a further depth of about 50—100 metres. — The throw of the mentioned great fault was about 80—110 metres. This is proven by the circumstance that the abundance of ore of the main-gallery level of the northern block is reached in this section only on the —100 metre level. The displacement is also indicated by a vertical shift of the mineral association. The veins of northerly strike were formed at the same time. More exactly speaking, the formation of the Károly vein has commenced somewhat earlier, i.e. the full development of this vein took a longer interval of time. The Károly and Arany Péter veins do not touch. However, their mineral association shows them to be of the same age. In our opinion, the formation of the veins of the area took place in two, partly coincident, phases. The first phase has yielded the almost perpendicular fissures of the Arany Péter and Károly veins. In the final stage of the formation of the older generation of the main minerals a set of new fissures in both directions was formed by the second phase of tectonics. The second generation of the main ore minerals was formed subsequantly. Meanwhile, the older ore was partially digested. The further development of the veins then proceeded along identical lines for both sets. However, interruptions, i. e. ceasings of solution transport, of variable duration have occurred in each vein. This is the reason why at the lines of intersection of the veins the bands carrying the young mineral association are intertwined in a dovetailing-like manner.