A Geoscience Digital Image Library

TitleOlivine-pyroxene andesite, Fish Lake, Oregon
DescriptionTypical andesites are extrusive igneous rocks containing plagioclase and one or more of the mafic minerals clinopyroxene, orthopyroxene, or hornblende. Although not typical, olivine is also present in some andesites. Andesites are commonly porphyritic. The fine groundmass between phenocrysts contains the same minerals that are present as phenocrysts, and may also contain quartz.
LocationUSA ▹ Oregon ▹ Jackson. Near Fish Lake.
PhotographerNessa Eull. 2001-05-15.
CollectionWard’s University Rock Collection #122.
Key wordsandesite, Oregon
Tech details738 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera, 60mm Nikon AF micro lens.
GeoDIL number450