Forelesninger holdt ved Advanced Study Institute of Feldspar - Oslo 1962
Lectures held at Advanced Study Institute of Feldspar - Oslo 1962

This study was undertaken by Eisinger ( 1960) primarily to determine if a zonal distribution of plagioclase composition exists in the metamorphic rocks of the Prison Hill-Brunswick Canyon area, and if plagioclase composition is correlative with metamorphic grade. If these relationships could be established they might be used as a basis on which to map the outer boundary of the contact metamorphic aureole, which is generally narrow and obscure in the studied area.

J. N. Swinderman made optical studies of plagioclase feldspars from the Prison Hill pluton to determine whether there is increased disorder in the plagioclase of marginal zones. D. B. Slemmons made the X-ray diffraction study of the plagioclase.