Optical data on some authigenic feldspars from Western Australia
- 1 March 1970
- journal article
- Published by Mineralogical Society in Mineralogical Magazine
- Vol. 37 (289), 588-592
- https://doi.org/10.1180/minmag.1970.037.289.08
Abstract
Summary: Authigenic envelopes up to 0·18 mm thick on clastic potassium feldspar grains from arkoses and subgreywackes of the Devonian Nannyarra Greywacke have been examined with the four-axis universal stage. The plane of the optic axes is parallel to (010) in some segments of individual envelopes and normal to (010) in others, and the range of 2Vα over all envelopes is from close to 0° to 65°. The optics are ascribed to modifications of potassium feldspar corresponding to high-and low-sanidine and orthoclase.Keywords
This publication has 2 references indexed in Scilit:
- A Study of Authigenic FeldsparsThe Journal of Geology, 1956
- Use of the universal stage in sedimentary petrographyAmerican Journal of Science, 1949