granodorit

Granodorit (more commonly called granodiorite) is a coarse-grained intrusive igneous rock intermediate in composition between granite and diorite. It is phaneritic, meaning its mineral grains are visible to the naked eye, and typically forms in large plutons and batholiths where magma cools slowly at depth in continental crust.

Mineralogy and texture: Granodiorite contains abundant plagioclase feldspar (usually more than K-feldspar), quartz in moderate amounts (commonly about 20–40%), and appreciable mafic minerals such as biotite, hornblende or pyroxene. The overall color ranges from light to medium gray, with darker specks from mafic phases. Texturally it is similar to granite but can appear slightly more mafic and less pink due to the lower potassium-feldspar content.

Formation and occurrence: Granodiorite is commonly associated with convergent plate margins and continental arc magmatism, where partial melting of subducted or lower crustal materials produces silica-rich magmas. It is widespread in many mountain belts and batholiths worldwide.

Uses and significance: Because of its durability and attractive granular appearance, granodiorite is used as dimension stone, crushed stone for construction, and occasionally for monuments and paving. In geology, its composition helps interpret magmatic processes and tectonic settings in crustal evolution.

Etymology and variants: The name derives from the combination of granite and diorite, reflecting its intermediate character; "granodorit" is an alternative transliteration used in some languages.