| 释义 |
▪ I. extrusive, n. Geol.|ɛkˈstruːsɪv|
[f. extrusive a.]
A (body of) rock formed by volcanic extrusion.
1909in Cent. Dict. Suppl. 1939A. Johannsen Descr. Petrogr. Igneous Rocks (ed. 2) I. i. 5 In this group are also included certain other rocks which, strictly speaking, are not extrusives, namely, the pyroclastics. 1962F. I. Ordway et al. Basic Astronautics v. 214 [Water] could be present as..water of crystallization in volcanic extrusives. 1984Bull. Geol. Soc. Amer. XCV. 433 The earliest preserved extrusives..are for the most part fragmental basalts and trachytes.
▪ II. extrusive, a.|ɛkˈstruːsɪv|
[f. L. extrūs- ppl. stem of extrūdĕre to extrude + -ive.]
a. Tending to extrude or thrust outwards.
b. Resulting from or characterized by extrusion.
c. Capable of being protruded.
1816Keatinge Trav. (1817) II. 24 These hills are not..the extrusive edges of strata, but rather elevated table land. 1848Johnston in Proc. Berw. Nat. Club II. 307 The shafts are extrusive, being pushed out like a telescope. 1886Proctor in 19th Cent. May 693 The immense extrusive power of the volcanoes of the tertiary era. |