| Igneous rock | |
 | |
| Composition | |
|---|---|
| oligoclase, otherplagioclase |
Trondhjemite is a leucocratic (light-colored)intrusiveigneous rock. It is a variety oftonalite in which theplagioclase is mostly in the form ofoligoclase.[1] Trondhjemites that occur in the oceaniccrust or inophiolites are usually calledplagiogranites.[2][3]
Trondhjemite is common inArcheanterranes occurring in conjunction with tonalite andgranodiorite as theTTG (tonalite–trondhjemite–granodiorite) orthogneiss suite.[4] Trondhjemitedikes also commonly form part of thesheeted dike complex of an ophiolite.[3]
The rock type was first described by V.M. Goldschmidt in 1916. The name of the rock type is derived from the city ofTrondheim, Norway.[1]
.png) | Thisigneous rock-related article is astub. You can help Wikipedia byexpanding it. |