dunite
/ˈdʌnʌɪt
/noun [mass noun] Geology
A green to brownish coarse-grained igneous rock consisting largely of olivine.The lowermost rocks are serpentinized dunite and harzburgite, which are best exposed in the NE of the ophiolite....
- Its lower part displays alternating bands of peridotite, pyroxenite, and dunite, but dunite is dominant throughout most (and especially the upper part) of the unit.
- In the field, the boundary between crustal units and mantle units is marked by a zone of sheared serpentinite, which overlies more massive largely serpentinized, harzburgite and dunite.
Origin
Mid 19th century: from the name of Dun Mountain, New Zealand, + -ite1.