| 释义 |
essexite, n. Petrogr.|ˈɛsɪksaɪt|
[f. the name of Essex County, Mass., where the first examples were found and described, + -ite1.]
Any crystalline igneous rock consisting of labradorite or similar plagioclase, alkali feldspar, and nepheline, together with various mafic minerals.
1891J. H. Sears in Bull. Essex Inst. XXIII. 146, I would, therefore, propose the name of Essexite for this ancient elæolite-zircon-syenite rock. 1954C. E. Tilley et al. Harker's Petrol. (ed. 8) vi. 78 The essexites of the Gran district in Norway sometimes contain a deep brown hornblende (barkevicite) in addition to the purplish augite. 1963[see titanaugite s.v. titano-2]. 1989Encycl. Brit. IV. 567/1 As the proportion of nepheline increases, essexite grades into theralite.
Hence esseˈxitic a., of or pertaining to essexite.
1927[see mugearitic adj. s.v. mugearite n.]. 1947Proc. Indian Acad. Sci. A. XXV. 75 It is deduced from these studies that the original magma is probably an ultrabasic (essexitic or picritic) type. 1974Geol. Mag. CXI. 343 The sill is of essexitic composition. |