Granitoid

A granitoid is a broad term referring to a diverse group of coarse-grained igneous rocks that are widely distributed across the globe, covering a significant portion of the Earth's exposed surface and constituting a large part of the continental crust ^[1]. These rocks are primarily composed ofquartz, plagioclase, and alkali feldspar.^[2] Granitoids range from plagioclase-rich tonalites to alkali-rich syenites and from quartz-poor monzonites to quartz-rich quartzolites.^[3] As only two of the three defining mineral groups (quartz, plagioclase, and alkali feldspar) need to be present for the rock to be called a granitoid, foid-bearing rocks, which predominantly contain feldspars but no quartz, are also granitoids.^[3] The terms granite and granitic rock are often used interchangeably for granitoids; however, granite is just one particular type of granitoid.

Granitoids are diverse; no classification system for granitoids can give a complete and unique characterization of the origin, compositional evolution, and geodynamic environment for the genesis of a granitoid. Accordingly, multiple granitoid classification systems have been developed such as those based on: geochemistry, modal content,^[jargon] emplacement depth, and tectonic regime.