Szakáll Sándor szerk.: A Szerencsi-dombság ásványai (Topographia Mineralogica Hungariae 3. Miskolc, 1998)

A Szerencsi-dombság ásványai (Szakáll Sándor & Kovács Árpád)

Topographia Mineralogica Hungáriáé Vol. III. 25-72. Miskolc, 1998 A SZERENCSI-DOMBSÁG ÁSVÁNYAI Minerals of the Szerencs Hills SZAKÁLL Sándor & KOVÁCS Áipád Abstract: Mineral parageneses of the Szerencs Hills are reviewed in a genetic subdivision. 1/ Rock-forming minerals of the main crystallisation phase of the rhyolite, dacite, and andésite volcanism are the following ones in decreasing order of frequency. Main components: quartz, sanidine, plagioclase, pyroxene, biotitc, accessory components: amphibole, rutile, ilmenite, magnetite, and zircon (Table I). 2/ Minerals formed under hypothermal (pneumatolytic) conditions within lithophyses of the volcanics: tridymite, quartz, biotite, hematite, ilmenite, and magnetite. Most frequent void-filling minerals are 1-3 mm, face-rich crystals of quartz and tridymite (Figs. 21., 22., 23.). 3/ Minerals formed within fissures and cavities of the volcanics under hydrothermal conditions: quartz, opal, hematite, cryptomelane, clinoptilolite, mordenite, slilbite, pyrite, and barite. There are numerous opal varieties in the region, especially in rhyolitcs. The best milk opal and jasper opal specimens are to be found in Ingvár Hill, while hyalite and precious opal occur in Hosszú Hill (Figs. I., IL, III., 18.). Minerals of hydrothermal ore indications are: acanthite, galena, marcasite, pyrite, sphalerite, and tetrahedrite. 4/ Oxidation zone minerals are: malachite, goethite, hematite, Mn-oxides, otavite, cerussite(?), and aurichalcite(?). The Legyesbénye quartzite quarry bears the most species. The occurrence of otavite is notable here (Fig. 26.). 5/ Postvolcanic parageneses: a/ zeolite zone: clinoptilolite, mordenite; b/ clay mineral zone: dickite, halloysite, illitc, montmorillonite, kaolinite, rectorite. There are numerous clay mineral deposits, dominated by kaolinite. c/limonite-hidrohematite zone: goethite, hematite; d/ kaolinite-adularia zone: kaolinite, adularia, quartz; e/ siliceous (partly alunite-kaolinite) zone: alunite, anatase, kaolinite, quartz, opal, jarosite, zircon, pyrite, barite, and marcasite. Parageneses tend to intcrfinger; some minerals (goethite, kaolinite) are to be found in all facies. Mineral formation was discontinuous: there are at least 4-5 generations of carbonates and of alunite. There are significant occurrences of alunite in the hills (e.g. Kassa Hill, Nyirjes Hill, Kővágó Hill). Alunite of Legyesbénye (quartzite quarry) has the most interest to mineralogists, bearing various element substitutions (Cu, Pb, Fe) (Figs. V., 32., 33., 34.). Trace element investigation of alunite, opal, and quartz show enrichment in silver, copper, lead, and titanium. 6/ Minerals of sedimentary rocks: In pyroclastics: mordenite, clinoptilolite, adularia. Pyroclastics display significant zeolitisation. There were attempts to utilize. Both in pyroclastics and in sand/sandstone: wood opal. The most famous mineral of the Szerencs Hills is the wood opal of Megyaszó, known since the 18th century. It has been studied by palaebotanists to date (Figs, title page, IV., 20.). The petrification perfectly preserved the structure of the plant remains (woods, branches, leaves etc.). In clay and lignite: gypsum, goethite, jarosite(V).