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

ized solutions did not take place along the total length of the fissure, as the percentage of ore-bearing vein sections decreases with depth. The solutions have apparently broken into the fissure from independent funnels situated some 50 to 150 metres apart. Once in the fissure, the solutions spread out to the entire length of the same, and having precipitated their mineral content, passed on upwards. The funnels could have been active simultaneously as well as alternatingly. This was presumably the way in which the telescope structure, characteristic of hydrothermal veins, came to exist. This assumption also explains the circumstance that the vertical zoning of the veins, observed in a number of places, also exists sometimes in the horizontal sense. This is especially apparent in the lateral section of the veins. Prior to the present author, this occurrence was studied ore microscopically by K. Sztrókay and S. Koch. The former has relegated the occurrence to the group of low-temperature effusive hydrothermal deposits, while the latter established the presence of wurtzite and considered the veins on this ground to have formed at a meso- to epithermal temperature. The mentioned authors have also made a detailed treatment of the mineral association. The sequence of formation of the ore minerals was determined by S. Koch. The repetition of ore microscopic investigation was made necessary by the large-scale mining and geological exploration begun in 1950, as the former investigators were only able to study minerals found on the dumps and in the then only partially explored Károly and Péter-Pál veins. Since that time a number of veins and vein systems were disclosed. Thus a comparative study of the mineral associations of the individual veins and of the vein systems of different strike has become necessary, so as to clear the genesis and the age relations of the same. In the course of this work no new mineral was observed. However, the mineral associations of the individual veins and their genetic interrelations have been determined. On the basis of his observations, the present author has to some extent modified the sequence of formation established by S. Koch. The frequency of the individual minerals of the parageneses was also estimated, regarding the present state of disclosure of the veins. In estimating, five categories were taken into consideration : predominant, very frequent, frequent, rare, very rare. According to ore microscopic investigation, the sequence of formation of ore minerals, as compared with the sequence established by S. Koch, is as follows : Results of the ore microscopical investigations of the veins Koch (1954) sphalerite II chalcopyrite II m area site pyrite II jarnesonite semseyite arsenopyrite tetrahedrite antimonite pyrite I galena I gold chalcopyrite I sphalerite wurtzite stannite bournonite galena II Kaszanitzky (1959) pyrite I galena I gold cbalcopyrite I sphalerite I wurtzite stannite bournonite galena II sphalerite tetrahedrite chalcopyrite II arsenopyrite jamesonite semseyite boulangerite (?) pyrite II antimonite marcasite pyrite III