- Relating to or denoting igneous rocks composed chiefly of mafic minerals. Compare with ultrabasic.More example sentences
- Variably serpentinized Devonian mafic and ultramafic intrusive rocks occur in the western and northern parts of the map area.
- A major source of iron, called iron laterite, is a type of residual deposit generated by the intense weathering of iron-rich rocks such as mafic and ultramafic volcanic rocks.
- The provenance of the feldspar-bearing Crocker Formation and younger sandstones indicates a granitic source character, which conflicts with the abundance of mafic and ultramafic basement rocks exposed throughout much of Sabah.
More definitions of ultramaficDefinition of ultramafic in:
- The British & World English dictionary