Alkaline Rocks and Carbonatites of the World

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

Chamdzhyak

stripes

Occurrence number: 
136-08-002
Country: 
Russia
Region: 
East Tuva
Location: 
Longitude: 96.8, Latitude: 53.52
Carbonatite: 
No

The Chamdzhyak massif includes peralkaline and calc-alkaline syenites and granosyenites. Small dykes and veins of riebeckite granite are present. The more alkaline varieties of rocks are most frequent in those parts of the intrusion where limestone country rocks are more abundant. The composition of the syenites is variable with alkali feldspar 32-84%, katophorite 1-9%, biotite 0-8%, pyroxene 0-8% and plagioclase 0-54%; magnetite is minor.

Age: 
K-Ar determinations on syenite gave 408 and 430 Ma (Kovalenko and Popolitov, 1970).
References: 

KOVALENKO, V.I. and POPOLITOV, E.I. 1970. Petrology and geochemistry of the REE of the alkaline and granite rocks from north-east Tuva. Nauka, Moscow, 158 pp.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith