| 释义 |
komatiite, n. Petrogr.|kəʊˈmætɪaɪt|
[f. the name of the Komati river, Transvaal, South Africa, site of the first occurrence to be so designated + -ite1.]
An ultramafic extrusive rock notably rich in magnesium, often with a characteristic spinifex texture.
1969M. J. & R. P. Viljoen in Geol. Soc. S. Afr. Special Publ. II. iv. 60 All of these peridotitic rocks have a distinctive and unusual chemical composition. They are unlike any class of peridotitic or picritic rock known and a new name, peridotitic komatiite,..has been proposed. Ibid. v. 89 It is suggested that these rocks, which have chemical affinities with the associated ultramafics, might well constitute a new class of basaltic rock and the name basaltic komatiite is proposed. 1977Jrnl. Petrol. XVIII. 321 Three types of komatiites are recognized: peridotitic, pyroxenitic, and basaltic komatiites. 1979Nature 5 Apr. 545/1 Gorgona is one of the rare places in the world where young pyroxenitic komatiites exhibiting typical quenched spinifex textures..occur. 1992S. P. Maran Astron. & Astrophysics Encycl. 547/1 A minor constituent of these ancient volcanic rocks..is..komatiite, which indicates that the early Earth had a hotter mantle and greater magma production than it does now.
Hence komatiˈitic a., of the nature of, containing, or resembling komatiite.
1975Nature 4 Dec. 413/2 Included in the DAT category are komatiitic tholeiites. 1989Jrnl. Petrol. XXX. 179 The komatiitic series will be hereafter divided into peridotitic.., pyroxenitic.., and basaltic. 1993P. Kearey Encycl. Solid Earth Sci. 355/1 The association of komatiites and komatiitic basalts is termed the komatiite suite or series. |