The Pyroxenes of the Alkaline Igneous Complexes of Eastern Uganda

Ruth C. Tyler and B. C. King
62 Hallgarth St., Durham1
Bedford College, London N.W.1
1Formerly of Bedford College and of King's College, London.

Summary: Chemical analyses, some optical data, and specific gravities are given for 57 pyroxenes from the alkaline rocks of Uganda. They are members of the diopside-hedenbergite-acmite series, the more diopsidic varieties occurring in rocks of the ijolite series and the more acmitic in syenites and carbonatites. TiO2 is highest in those pyroxenes from rocks that do not contain melanite. The refractive indices and specific gravities are controlled by the Fe2+/Mg ratio in the diopsidic pyroxenes and by the Fe3+ content in the acmitic members. Paragenesis is discussed briefly.

Mineralogical Magazine; March 1967 v. 36; no. 277; p. 5-21; DOI: 10.1180/minmag.1967.036.277.02
© 1967, The Mineralogical Society
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