komatiite
/kəˈmatɪʌɪt
/noun [mass noun] Geology
A magnesium-rich extrusive rock, typically with a characteristic texture of criss-crossing olivine crystals.This rhythmic layering is common within komatiite flows at Kambalda, and is inferred to reflect incremental emplacement by endogenous growth....
- The nature and distribution of vesicles in thick komatiite flows indicates two stages of vesiculation.
- Alternative origins include secondary influx due to devolatization, physical incorporation, and/or thermal incorporation of sediment resulting from komatiite lava flow on hydrous sediments.
Derivatives
komatiitic
- Massive to pillowed tholeiitic basalt, komatiitic basalt and ultramafic rocks form a series of partly overlapping lensoidal bodies with typical sigmoidal outcrop patterns.
- The Reliance flow fields and associated sills are considered to represent, respectively, the volcanic and subvolcanic phases of komatiitic sill-flow complexes, each about 100 km in diameter, scattered across the craton.
- The widespread but discontinuous Reliance unit comprises a series of essentially discrete komatiitic flow fields that are submarine in most regions but partly emergent at Belingwe.
Origin
1960s: from Komati (the name of a river in southern Africa) + -ite1.