Abstract
Large phenocrysts of clinopyroxene, amphibole in the Godóvár tuff show normal zoning with mg-values decreasing from the center towards the border zones. Clinopyroxenes exhibit a primitive Cr-diopsidic (Mg48Fe7Ca45) core which with a sudden change in the composition is surrounded by an augitic rim (Mg44Fe14Ca42). No such abrupt change can be observed in amphibole crystals which are typical pargasites and only the outermost zones may pass into the magnesio-hastingsite field. It is argued that the Cr-diopside may have separated from a basaltic liquid at depths greater than about 18 km, while the other pyroxene zones with the pargasite and plagioclase crystals accumulated in a storage chamber at a depth of about 12–15 km.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Aoki K (1970) Petrology of kaersutite-bearing ultramafic and mafic inclusions in Iki Island, Japan. Contrib Mineral Petrol 25:270–283
Brooks CK, Platt RG (1975) Kaersutite-bearing gabbroic inclusions and the late dike swarm of Kangerdlugsuaq, East Greenland. Mineral Mag 40:259–283
Embey-Isztin A (1976) Amphibolite/lherzolite composite xenolith from Szigliget, north of the Lake Balaton, Hungary. Earth Planet Sci Lett 31:297–304
Holloway JR, Burnham CW (1972) Melting relations of basalts with equilibrium water pressure less than total pressure. J Petrol 13:1–29
Kushiro I (1962) Clinopyroxene solid solutions. Part I. The CaAl2SiO6 component. Japan J Geol Geogr 33:212–220
Kushiro I (1969) Clinopyroxene solid solutions formed by reactions between diopside and plagioclase at high pressures. Mineral Soc Am Spec Pap 2: 179–191
Leake BE (1978) Nomenclature of amphiboles. Mineral Mag 42:533–563
Liffa A, Vigh Gy (1937) Adatok a Börzsöny-hegység bányageológiai viszonyaihoz. (Contributions to the geological features of the Börzsöny Mts.) Magy Kir Földt Int Évi Jel 1930-32 évröl: 235–283
Muñoz M, Sagredo J (1974) Clinopyroxenes as geobarometric indicators in mafic and ultramafic rocks from the Canary Islands. Contrib Mineral Petrol 32:139–147
Noske-Fazekas G (1972) Feldspatuntersuchungen an den Andesiten des Südteiles des Börzsöny-Gebirges. Ann Hist-nat Mus Nat Hung 64:5–17
Noske-Fazekas G (1974) Feldspatuntersuchungen an den Dazitvorkommen des Südteiles des Börzsöny-Gebirges. Fragm Min Pal 5:5–19
Noske-Fazekas G (1977) Feldspatuntersuchungen am Andesitvorkommen des Róka-Berges bei Szokolya Ungarn. Ann Hist-nat Mus Nat Hung 69:13–21
Noske-Fazekas G (1979) Einige Daten zur optischen Untersuchung von Andesiten des Börzsönygebirges, Ungarn. Ann Hist-nat Mus Nat Hung 71:5–14
Noske-Fazekas G (1980) Statistical investigations of plagioclase twin laws in lavas erupted between the Danube and the Central Börzsöny Mountains (Hungary). Ann Hist-nat Mus Nat Hung 72:11–18
Pantó Gy (1970) Vulkanológiai vizsgálatok a Mátrában és a Börzsönyben. II. rész: A Börzsöny hegység északi részének harmadidoszaki vulkanizmusa. (Volcanological investigations in the Mátra and Börzsöny Mts. Part II: The Cenosic volcanism of the northern part of the Börzsöny Mts). Akadémia ed, Budapest, pp 163–302
Yagi K, Onuma K (1967) The join CaMgSi2O6-CaTiAl2O6 and its bearing on the titanaugites. J Fac Sci, Hokkaido Univ ser 4, 13:463–483
Yoder HS, Tilley CE (1962) Origin of basalt magmas: an experimental study of natural and synthetic rock systems. J Petrol 3:342–542
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Embey-Isztin, A., Noske-Fazekas, G. Chemical zoning in the large phenocrysts of the Godóvár tuff, Börzsöny Mts., Hungary. Contr. Mineral. and Petrol. 77, 325–331 (1981). https://doi.org/10.1007/BF00371561
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00371561