Chemická variabilita granitu typu Černá kočka čisteckého masivu
Josef Franče, Ferry Fediuk
The Černá kočka muscovite alkali feldspar granite, occurring on the SE border of the Čistá granitoide massif, has been hitherto chemically characterized by a single analysis only. The present contribution, using 46 new unpublished chemical analyses from a technological report, offers in a series of diagrams a comprehensive petrochemical characteristic of this rather exceptional. rock and compares it with the previous published analysis. The Černá kočka granite differs markedly from the main granitoid types of the Čistá-Jesenice Pluton (the Tis granite, Petrohrad granodiorite, Čistá central and Čistá peripheral granodiorite) by its specific geochemistry (namely high-K character, higher SiO2 and alkalis and extremely low TiO2, Fe2O3 tot , MgO and CaO contents), by its mineralogy (especially by the absence of biotite and the presence of albite and ± tourmaline) and by its autonomous geological setting and by the supposed younger age of the emplacement.