ultramaficadj.n.
/ʌltrəˈmafɪk/ Geology.
Of an igneous rock: composed chiefly of mafic minerals. Also as n.
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the world > the earth > structure of the earth > constituent materials > rock > igneous rock > [noun] > mineral composition
fem1902
sal1902
ultramafic1933
ultrabasic1964
komatiite1969
the world > the earth > structure of the earth > constituent materials > rock > igneous rock > [adjective] > mineral composition
basic1854
acid1859
ultrabasic1881
femic1902
sal1909
ultramafic1933
komatiitic1975
1933 R. A. Daly Igneous Rocks & Depths of Earth ii. 31 The more important groups [of igneous rocks] are the granite clan.., the ultramafic clans, and the ‘feldspathoidal’ clans.
1933 R. A. Daly Igneous Rocks & Depths of Earth xxii. 565 Each of the ultramafic and ultrabasic species..treated in this chapter has its own unsolved problems.
1948 Bull. Oregon State Dept. Geol. & Mineral. 39 8 The ultramafics include bodies of dunite, pyroxenite, and gabbro which have been extensively altered to hornblendite and serpentine.
1965 G. J. Williams Econ. Geol. N.Z. x. 143/1 The useful non-metallic minerals are more abundant in those ultramafics which have been subjected either to metamorphic or metasomatic changes.
1967 P. J. Wyllie Ultramafic & Related Rocks 1/1 Ultramafic monomineralic rocks composed of the following mafic minerals would certainly be ultrabasic..forsterite..fayalite..hornblende..biotite.
1971 I. G. Gass et al. Understanding Earth i. 23/1 Only in the ultramafic rocks..does Al2O3 fall to significantly lower values than those quoted.
This entry has not yet been fully updated (first published 1986; most recently modified version published online June 2018).
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adj.n.1933