http://resource.geosciml.org/classifier/cgi/lithology/dacite
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| definition | Fine grained or porphyritic crystalline rock that contains less than 90 percent mafic minerals, between 20 and 60 percent quartz in the QAPF fraction, and has a plagioclase to total feldspar ratio greater than 0.65. Includes rocks defined modally in QAPF fields 4 and 5 or chemically in TAS Field O3. Typcially composed of quartz and sodic plagioclase with minor amounts of biotite and/or hornblende and/or pyroxene; fine-grained equivalent of granodiorite and tonalite. | |||||||||||
| example | rhyodacite | |||||||||||
| source | LeMaitre et al. 2002 | |||||||||||
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| in scheme | simplelithology original | |||||||||||