Igneous rock | |
Composition | |
---|---|
Classification | Felsic |
Plagioclase and K-Feldspars, depleted in quartz | |
Texture | Phaneritic |
Equivalents | Trachyte extrusively |
Syenite is a coarse-grained intrusive igneous rock with a general composition similar to that of granite, but deficient in quartz, which, if present at all, occurs in relatively small concentrations (< 5%). It is considered a granitoid. Some syenites contain larger proportions of mafic components and smaller amounts of felsic material than most granites; those are classed as being of intermediate composition.
The extrusive equivalent of syenite is trachyte.[1]
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