Alkaline Rocks and Carbonatites of the World

Setup during HiTech AlkCarb: an online database of alkaline rock and carbonatite occurrences

Kushva

stripes

Occurrence number: 
136-20-001
Country: 
Russia
Region: 
The Urals
Location: 
Longitude: 59.78, Latitude: 58.3
Carbonatite: 
No

Veins of nepheline (liebeneritic) syenites and nepheline syenite pegmatites up to 2 m thick are present in the intrusion, which is essentially of syenites. The nepheline syenites of the veins are variable in composition and structure with both trachytic and massively textured types. They contain up to 20-25% of nepheline, which may also be pseudomorphed by cancrinite, analcime, zeolites and spreustein, 65-70% of feldspar, including microperthite and albite-oligoclase, and 5-10% of aegirine-augite, salite, hastingsite and lepidomelane. Accessory minerals, forming about 2.5% of the rocks, include melanite, titanite, orthite, magnetite and apatite.

Age: 
K-Ar on syenites gave 369-389 Ma (Levin, 1974).
References: 

BORODIN, L.S., LAPIN, A.V. and PYATENKO, I.K. 1974. Alkaline provinces of Europe. In L.S. Borodin (ed), Principal provinces and formations of alkaline rocks. 11-90. Nauka, Moscow.
LEVIN, V.Y. 1974. The alkaline province of the Ilmenogorsk-Vishnevy Gory (formation of the nepheline syenite of the Urals). Nauka, Moscow. 224 pp.
LEVIN, A.Y., PETROV, V.I. and LEVINA I.A. 1973. Experience of the facial and formation analyses of the nepheline syenite of the Urals. In. Problems of the petrology of the Urals. Proceedings of the Institute of Geology and Geochemistry, Sverdlovsk 100: 134-54.

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