Fehér Béla (szerk.): Az ásványok vonzásában, Tanulmányok a 60 éves Szakáll Sándor tiszteletére (Miskolc, 2014)
Ozdín Daniel - Szakáll Sándor: A Miskolc-lillafüredi axinit-(Fe) kémiai összetétele
Chemical composition of axinite-(Fe) from Miskolc-Lillafiired 205 (Zn Ka), pure Ni (Ni Ka), SrTi03 (Sr La), baryte (Ba La), albite (Na Ka), orthoclase (K Ka), LiF (F Ka) and NaCl (Cl Ka). Some minerals were identified by EDS spectra on electron microprobe in the workplace referred to above. Back-scattered electron images were conducted on the same instrument at an accelerating voltage of 15 kV with a beam current of 20 or 60 nA. 3. Characteristics of the occurrence Hydrothermal veins with axinite are situated in the Triassic volcanites of Bükk Mts. in the Szinva metabasalts (Ladinian-Camian; Lexa et al., 2000). Szinva Metabasalt Formation was described by Haas (1993). Dódony (in Szakáll & Földvári, 1995) identified tremolite and clinochlore in these metabasalts using TEM and electron microprobe. Szoldán (1990) described actinolite, pumpellyite, albite and chlorite as products of weak epimeta- morphism. Metabasalts rise to the surface mostly in the central part of Triassic (Ladinian- Camian) metamorphosed, light grey, massive limestones, less oolitic limestones, variegated sandstones and marls of Bükk (Scythian-Anisian; including Anisian Hámor Dolomite) and metamorphosed cherty limestones of the Túrna sequence and Bükk (Late Triassic) (Lexa et al., 2000). Geological map of the studied area is in the Fig. 1. Szentpétery (1944-1945) first described paragenesis of quartz-calcite-albite veins in the metabasalts near Miskolc-Lillafiired. Axinite was first discovered in these veins by Szakáll (1992, 1993) and later analytical data, as morphological crystallography, average chemical composition and DTA, were published by Szakáll & Földvári (1995). These authors also identified a mineral from the epidote group, hematite and Cu mineralization represented by primary chalcopyrite, chalcocite, bomite, galena and pyrite. Secondary minerals described here are malachite, covellite, goethite and especially bluish-green chryso- colla. 4. Results Hydrothermal veins with axinite occur in metabasalts ~ 1.5-2 km SSW of Lillafüred near Miskolc. Thin sections show a highly recrystallized fine-grained texture of this metabasalt. The metabasalt is characterized by epidotization to saussuritization, locally chloritization occurs. Saussuritization is metamorphic-hydrothermal process in which original feldspar and other silicates transform to the mixture composed of especially albite and minerals of epidote group ± calcite. The metamorphic process is not characterized only by higher temperature but also by higher pressure, which is obvious from directed pressure cracks in axinite-(Fe), repaired by quartz. Cataclasis can be observed especially on fractured epidote crystals occurring on calcite veinlets. Axinite-(Fe) - Ca4Fe2+2Al4[B2Si8O30](OH)2 - occurs in the form of completely restricted, euhedral crystals (Fig. 2) and especially on the individual veins the crystals are subhedral to anhedral. It occurs mainly in association with calcite and albite; however it is frequently crossed by hydrothermal quartz veins (Fig. 3). Quartz fills parallel fractures caused by elevated pressure (Fig. 4).
