Two-garnet rodingite from Amador County, California

Journal of Research of the U.S. Geological Survey
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Abstract

Two distinct phases of garnet have been discovered in rodingite from Amador County, Calif. The two garnets are hydrogrossular and (hydro?) grossular-andradite. Only one, generally hydrogrossular, has been reported in rodingitcs studied by other workers. The rodingite of this study formed from a mafic dike with abundant euhedral plagioclase laths. The hydrogrossular is concentrated within the areas of these laths and is volumetrically about as abundant. The (hydro?) grossular-andradite is concentrated in the groundmass and as incursions into the plagioclase laths. The garnets apparently grew during one general episode of metasomatism, and their spatial distribution and compositions were controlled principally by the unequal distribution of iron and aluminum caused by the presence of plagioclase laths (and mafic minerals?) in the original unaltered dike.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Two-garnet rodingite from Amador County, California
Series title Journal of Research of the U.S. Geological Survey
Volume 1
Issue 6
Year Published 1973
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Description 8 p.
First page 665
Last page 672
Country United States
State California
County Amador County
Online Only (Y/N) N
Additional Online Files (Y/N) N