adjective
- containing very little silica and having a high proportion of iron and magnesium minerals
Usage: geology
Examples
- The ultrabasic rocks found in the ocean floor are rich in olivine and pyroxene.
- Peridotite is a common type of ultrabasic igneous rock.
- The geologist identified ultrabasic minerals in the core samples.
- Ultrabasic magmas have very low silica content compared to granitic melts.
- The ophiolite complex contains ultrabasic rocks from the upper mantle.
- Serpentine forms when ultrabasic rocks undergo hydrothermal alteration.