camptonite Petrogr.
(ˈkæmptənaɪt)
[a. G. camptonite (H. Rosenbusch Mikrosk. Physiogr. d. Min. und Gesteine (ed. 2, 1887) II. 333), f. Campton, a town in New Hampshire, U.S.A.: see -ite1.]
Any of a group of dark-coloured, usu. porphyritic dike-rocks resembling basalt and typically consisting of phenocrysts of hornblende or barkevikite in a matrix of plagioclase.
| 1895 Dana Man. Geol. (ed. 4) 87 Camptonyte.—Rock resembling diabase and doleryte. Consisting of hornblende (as an original mineral of the rock) and probably anorthite. 1901 Nature 19 Sept. 513/1 The sills of camptonite and felsite intrusive in the Cambrian rocks. 1961 F. H. Hatch et al. Petrol. Igneous Rocks (ed. 12) iv. ii. 475 Localized intrusions of basic lamprophyric rocks including camptonites and monchiquites occur in or near the Ayrshire vents. |