granodiorite A coarse-grained igneous rock consisting of essential quartz, plagioclase feldspar, alkali feldspar, biotite, and hornblende, with accessory sphene, apatite, and magnetite. Plagioclase is the dominant feldspar in the rock, equal to or greater than two-thirds of the total feldspar present. Where alkali feldspar is completely, or almost completely suppressed, the rock is known as a ‘trondhjemite’ or, more generally, ‘plagiogranite’. Granodiorites are commonly found as intrusions into the crust above subduction zones, and are the plutonic equivalent of extrusive dacites.
More From encyclopedia.com
Iron Ores , Rocks Rocks are composed of minerals, which are natural inorganic (nonliving) substances with specific chemical compositions and structures. A rock m… Rock , rock1 / räk/ • n. 1. the solid mineral material forming part of the surface of the earth and other similar planets, exposed on the surface or underly… Igneous Rocks , Igneous rocks are formed by the cooling and hardening of molten magma. The word igneous comes from the Latin word igneus, meaning fire, and there are… Trachyte , trachyte Fine-grained volcanic rock of the alkaline series of intermediate rocks. Trachyte is the volcanic equivalent of syenite. trachyte gritty vol… Country Rock , Country rock The term country rock refers to a body of rock that receives or hosts an intrusion of a viscous geologic material. Intrusions into count… Metamorphic Rocks , Metamorphic rock is rock that has changed from one type of rock into another. The word metamorphic (from Greek) means “of changing form.” Metamorphic…
About this article
Updated About encyclopedia.com content Print Article
You Might Also Like