stripes
Occurrence number:
174-00-023
Country:
United States
Region:
Montana
Location:
Longitude: -113.9, Latitude: 46.27
Carbonatite:
No
Published information regarding the Skalkaho intrusion is sparse. It is an elongate complex of about 7x2 km consisting of pyroxenites, syenite and pegmatitic mafic rocks, and is intruded by a variety of alkaline dykes. The pyroxenites vary from almost monomineralic salite rocks to biotite (vermiculite) and amphibole-bearing varieties with abundant sphene, apatite and magnetite. The syenites are slightly quartz normative and contain aegirine-augite. Marginal fenites occur.
References:
ARMBRUSTMACHER, T.J. 1982. Geochemical characteristics of rocks in alkaline intrusive complexes, northwestern Montana: preliminary results. Abstracts with Programs, Geological Society of America, 14: 302.
T.J. ARMBRUSTMACHER, personal communication, 1984.
Location: