Blairmorite

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A specimen of blairmorite from the Crowsnest Formation. The amber mineral is analcime, the pale mineral is sanidine and the small black minerals are melanite garnet.

Blairmorite is a rare porphyritic volcanic rock characterized by dominant analcime phenocrysts in a matrix of analcime, sanidine and alkalic pyroxene with accessory titanite, melanite and nepheline. It was named after the community of Blairmore in southwestern Alberta, Canada.[1][2]

This extrusive igneous rock is known from only two geological formations worldwide. The foremost blairmorite occurrence is the Crowsnest Formation in the Canadian province of Alberta where it is associated with agglomerates and tuffs from explosive eruptions. The other locality is the Lupata Gorge in Mozambique.[1]

References

  1. 1.0 1.1 Pearce, T.H. "Analcime phenocrysts in igneous rocks: Primary or secondary? – Discussion" (PDF). American Mineralogist 78: 225-229, 1993. Retrieved 2014-10-06.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  2. Johannsen, A. 1933. A descriptive petrography of the igneous rocks, Appendix III, p. 244. Univ. of Chicago Press.