Alkaline Rocks and Carbonatites of the World

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

Itcha Mountains


Occurrence number: 
British Columbia
Longitude: -124.83, Latitude: 52.72

The Itcha Mountains (or Range) are one of the centres of the Anahim Volcanic Belt and consist of a central shield volcano amidst Miocene and Quaternary plateau lavas. The mountains do not appear to have been studied in great detail petrologically. The principal rock types appear to be alkali olivine basalts, hawaiites and basanites. Two examples of the basanites investigated by Nicholls et al. (1982) include modal leucite and leucite plus nepheline. These rocks contain olivine phenocrysts and one of them plagioclase phenocrysts, in a groundmass of olivine, plagioclase, pyroxene, opaques, leucite and nepheline. One of five hawaiites studied contains modal nepheline. Lherzolite xenoliths occur in the basanites. Rock and microprobe analyses of all the major minerals are given by Nicholls et al. (1982), and Stout and Nicholls (1983) discuss the origin of the hawaiites.


Mines, Geological Surveys Branch, Geological Report, 53: 1-35.
NICHOLLS, J., STOUT, M.Z. and FIESINGER, D.W. 1982. Petrologic variations in Quaternary volcanic rocks, British Columbia, and the nature of the underlying upper mantle. Contributions to Mineralogy and Petrology, 79: 201-18.
STOUT, M.Z. and NICHOLLS, J. 1983. Origin of the hawaiites from the Itcha Mountain Range, British Columbia. Canadian Mineralogist, 21: 575-81.

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