Alkaline Rocks and Carbonatites of the World

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

Botogol

stripes

Occurrence number: 
136-07-008
Country: 
Russia
Region: 
East Sayan
Location: 
Longitude: 100.75, Latitude: 52.33
Carbonatite: 
No

Botogol occupies an area of 10 km2. The intrusion comprises nepheline and peralkaline syenites containing a variety of xenoliths including limestone, quartzite and schist. The country rock limestones near the contact with the alkaline massif are metamorphosed with the formation of andradite, diopside andorthoclase while nepheline, apatite, zircon and cancrinite are present in some rocks. The massif has a zonal structure with nepheline syenites, together with small juvite and ijolite bodies, towards the centre and nepheline-free syenites at the margins. The nepheline syenites have a trachytic texture and comprise microcline (40-60%), nepheline (20-40%) and aegirine-hedenbergite (15-30%). The syenites are predominantly leucocratic rocks, with modal aegirine-hedenbergite varying from 15 to 30%,but in the vicinity of the outer contact the proportion of dark minerals increases and they become more melanocratic. Within the massif large concentrations of graphite have been discovered, the majority of these occurrences being related to xenoliths of carbonate rocks and localized in nepheline syenites and occasionally in peralkaline pyroxene syenites. For a detailed account of rock and mineral compositions see Lobzova (1975) and Kost'uk and Bazarova (1966).

Economic: 
About 30 graphite bodies have been located in the complex, mining having been confined to the northern area.
Age: 
K-Ar determinations on biotite gave 324±12 Ma and on nepheline 378±12 Ma (Lobzova, 1975).
References: 

KOST'UK, V.P. and BAZAROVA, T.U. 1966. Petrology of the alkaline rocks from the eastern part of the East Sayan. Nauka, Moscow. 168 pp.
LOBZOVA, R.V. 1975. Graphite and alkaline rocks of the Botogol massive area. Nauka, Moscow. 123 pp.

Map: 
Fig. 2_151. Botogol (after Lobzova, 1975, Fig. 2).
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith