Transitional-primitive Boundary in Calcic Plagioclase

Content Provider	Semantic Scholar
Author	Tasr
Copyright Year	2007
Abstract	Variation of reciprocal angle 7* with respect to a refractive index in four specimens of plagioclase from Greenhills, Blufi Peninsula, Southland, New Zealand, suggests a discontinuity rather than a flexure in unit cell geometry between Anno r-0, 6. This break, which probably represents the boundary between transitional anorthite and primitive anorthite, is also indicated by plotting 7* against mol percent anorthite after the manner proposed by Doman et at, (1965). The occurrence of two structurally distinct tlpes of plagioclase on opposite sides of the proposed break is supported by single crystal X-ray study of the
File Format	PDF HTM / HTML
Alternate Webpage(s)	http://www.minsocam.org/ammin/AM55/AM55_1273.pdf
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article