Experimental Studies of Igneous Rock Series: The Farrington Complex, North Carolina, and the Star Mountain Rhyolite, Texas
- Creators
- Gibbon, D. L.
- Wyllie, P. J.
Abstract
The phase relationships of four specimens from the Farrington Complex ranging in composition from granite to tonalite, and of four specimens from the Star Mountain Rhyolite, have been determined in the presence of 15-20 weight per cent H_2O in the pressure range from 1 to 3 kb. PT curves have been located for the beginning of melting and for the complete melting of quartz, alkali feldspar, and plagioclase. Glass percentages have been determined for representative samples by point counting in polished thin sections. The melting relationships for these two widely different series of rocks aid in defining the primary phase volumes in the "Granodiorite Tetrahedron." It has not been possible experimentally to reproduce the unusual natural phenocryst-groundmass relationships of the Star Mountain Rhyolite; this failure is attributed at least partly to the experimental condition of excess water, and confirms the conclusion, drawn from petrographic evidence, that these magmas were erupted with very low water contents.
Additional Information
© 1969 University of Chicago Press. Manuscript received April 27, 1968; revised June 27, 1968. The research reported in this study was supported by NSF grant GP-3440. Some costs of manuscript preparation were covered by NSF grant GA-923 at the University of Chicago. A.J. Piwinskii provided much technical assistance and discussion on the meaning of the results. E.W. White was of great assistance during probe runs.Additional details
- Eprint ID
- 64089
- Resolver ID
- CaltechAUTHORS:20160129-100248137
- GP-3440
- NSF
- GA-923
- NSF
- Created
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2016-01-29Created from EPrint's datestamp field
- Updated
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2019-10-03Created from EPrint's last_modified field
- Caltech groups
- Division of Geological and Planetary Sciences