A dark, medium-grained igneous rock, typically with ophitic texture, containing plagioclase, pyroxene, and olivine. It typically occurs in dykes and sills.
- ‘These supracrustal rocks are intruded by dolerite dykes that have been deformed and metamorphosed together with the country rock.’
- ‘We reached Fault Bluff, a dark angular mountain with faulted dolerite rock, around 10: 00 P.M. that night.’
- ‘Neither had iron tools and instead used such hard stones as flint, jade, dolerite, basalt, and serpentine to make axes, knives, and chisels.’
- ‘Many tales have been told about the impressive arch that was named in 1823 by the crew of the British survey ship, the Barracouta, because of the portal carved through an island rock castle with sheer dolerite walls.’
- ‘Dark dolerite mountains of the Warren Range had a light snow cover that accentuated the flow banding in the rock.’
Mid 19th century from French dolérite, from Greek doleros ‘deceptive’ (because it is difficult to distinguish from diorite).