Szakáll Sándor - Weiszburg Tamás szerk.: A telkibányai érces terület ásványai (Topographia Mineralogica Hungariae 2. Miskolc, 1994)
Telkibánya környékének kőzetföldtani felépítése és fejlődéstörténete (Kozák Miklós)
In the centre of the area, nearly concomitantly with the blocked acid (high) member of the augite- and hyperstene-containing andesitic sequence (10) (Fig. 8) was formed the extensive andesitic volcanic-subvolcanic rock mass the most part of whose material, having been exposed to syngenetic potassium metasomatism, was transformed into pseudotrachite (8) with 8-14 % K2O content. The complex process of metasomatism, the concomitant ore mineralization and ascendent-descendent rock transformation was elucidated by Széky-Fux (1964,1966,1970). The rock is called pseudotrachite only if the K2O content exceeds 8 %, below that value it is referred to as trachitic andésite, or something else. The process of transformation of the andesitic material takes place in the following way: pyroxene-orthoandesite m the matrix. The replacing monoclinic adularia appears in characteristic rhomboidal sections (Fig. 9), in addition, sanidine and triclinic K-feldspar were formed as pseudomorphosa after plagioclase. In the area of Kánya Hill, Gyepű Hill and Nagyhasdát Hill a system of siliceousore veins appear in outcrops, with nearly North-South strike direction. The course of these determined the ways of the one-time open-pit and underground mining activities. Potassium-metasomatism and silicification well exceed the borders of pseudotrachite and effect the rock masses of the environment, as well. This fact accounts for the development of the genetically closely connected siliceous rocks (7), such as hydroquartzite (h), geyserite (g) and limnoquartzite (1), which can be found as eroded remains now. Attached to these are perfect quartz crystals, remains of vein-filling quartz, jaspilite and striped calcedony, frequently occurring on the surface, embedded in soil and bedloads of streams. The centre, at Kánya Hill, is surrounded in the North and particularly in the South by large masses of unique rhyolitic foam-lava formations (6, 4, 5). These acid lava rocks, closely entwined and being in genetic connection with one another have been investigated by many researchers. The up-to-date classification of these formations on the basis of their fine structure was performed by Panto (1961, 1964, 1966) and Ilkey-Perlaky (1962,1966,1967,1972,1973,1978). Owing to their great variety, these rock types cannot be characterized in a uniform way. The sides of Ósva Valley, South-East of Telkibánya, are built up of vast masses of fluidal rhyolite lava rock (Fig. 10), on whose surface its vitreous variants, perlite, are settled as upwardly thinning, lens-like bodies. The grey-veined fluidal rhyolite (6) is the most variegated rock of the mountain region, characteristic of which is the whimsical alternation of millimetric-centimetric spots and bands of the grey-black, volatile-deficient perlitic vitreous phase and the pink-coloured, volatile-rich litoidic one. Owing to the enrichment of volatiles the spherical litoid segregations of 1-40 cm in diameter, gas sacks elongated along the planes of laminar movement with enclosed shell-like flanges are frequent in them (Fig. 11). In the basic material of the rocks there appear, in large masses, radial-fibrous-structure spherocrystals with potash feldspar - cristobalite composition.
