Plagioclase-Ca-Rich-Nepheline Intergrowths in a Syenite from the Marangudzi Complex, Rhodesia

C. M. B. Henderson and F. G. F. Gibb
Department of Geology, The University, Manchester M13 9PL, England

Summary: Nepheline in a basic syenite from the Marangudzi complex is relatively Ca-rich with CaO from 1·9 to 2·4 (wt) %. This Ca-rich nepheline sometimes occurs in intimate intergrowths with plagioclase (andesine). These intergrowths are thought to have formed at temperatures in the order of 750°–850°C by resorption of plagioclase with simultaneous replacement by nepheline.

Mineralogical Magazine; June 1972 v. 38; no. 298; p. 670-677; DOI: 10.1180/minmag.1972.038.298.03
© 1972, The Mineralogical Society
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