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MONZONITE |
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Typical Minerals PLAGIOCLASE - 50-100%Orthoclase - 10-35% Mafics - < 10% Quartz - 0-5% | Description
Monzonite is one of three rocks dominated by feldspar (the others being anorthosite and syenite) with occasional other minerals thrown in in lesser amounts (although the rock can go 100% plagioclase.) The plagioclase is sodium rich, unlike anorthosite which is calcium rich.Because monzonite is light colored it is often confused with granite but granite has quartz >20%. Monzonites with quartz 5-20% are "quartz monzonites." Less than 5% quartz and the rock is just monzonite. |
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Tectonic Association
Monzonite is not a common rock, but is typically found around the edges of other felsic plutons, such as plagiogranites or granodiorites. That is, it is typical of continents.Tectonic Cross Section - pdf version |
Last Update: 9/29/00 | e-mail: (Fichtels@jmu.edu) |