Fragmenta Minerologica et Palaeontologica

Author(s): Noske-Fazekas, G.
Title: Feldspatuntersuchungen an den Dazitvorkommen des Südteiles des Börzsöny-Gebirges
Title: Földpát vizsgálatok a Börzsönyhegység déli területeinek dácitelőfordulásain
Year: 1974
Volume: 5
Pages: 5-16.

Abstract: The elaboration of the occurrences of dacite using universal stage method, has been carried out as a continuation of the research on feldspars of the andésite types from the southern Börzsöny Mountains. The western dacite occurrence (Szob, Csákhegy) differs considerably from the eastern one (Nógrád, Várhegy) in mineral composition and in the An-content of plagioclases, a fact which is also revealed by the chemical analyses. While plagioclases of the biotite dacite have an An-content of 41, 7 per cent, those of the horblende dacite have 66, 5 per cent, the latter walueis similar in the andésites of the same area. The twin laws are the same in both rocks, but albite twins are more abundant in the dacites.

Journal: Fragmenta Minerologica et Palaeontologica
Journal abbreviation:
ISSN: 0367-2697
Publisher: Népművelési Propaganda Iroda, Budapest
Editor(s): Nagy, I. Z. & Nemes, I.