geologic, a.
(dʒiːəʊˈlɒdʒɪk)
[f. geolog-y + -ic.]
1. a. Of, pertaining to, or derived from geology; such as is described, investigated, or ascertained by geology. geologic time = geological time (see next); chiefly U.S.
There is now a slight distinction in usage between geologic and geological: the former tends to be used only as an epithet of things forming part of the subject-matter of the science: we may say a geologic epoch, but hardly a geologic student, a geologic theory.
| 1799 Kirwan Geol. Observ. 56 The most unequivocal geologic proofs of a general deluge. 1830 Blackw. Mag. XXVIII. 248 Descriptive sketches of our planet..with reference to its geologic structure. 1856 Emerson Eng. Traits, Land Wks. (Bohn) II. 18 It is written only in the geologic strata. 1861 Goldw. Smith Lect. Mod. Hist. 19 The vast length of geologic..time. 1863 J. G. Murphy Comm. Gen. i. ad fin., The last of those geologic changes which our globe has undergone. 1872 W. S. Symonds Rec. Rocks iv. 104 In far later geologic epochs, new volcanic vents poured forth their lavas. 1886 Mallock Old Order Changes II. 193 Found in some curious geologic formation. 1955 Sci. Amer. Mar. 82/1 Throughout geologic time, as far back as we can read the rocks, the continents have repeatedly been invaded by the oceans. 1968 Dayhoff & Eck Atlas Protein Sequence & Structure 1967–68 74/1 Geologic time, a time scale related to, and comparable with, the age of the earth. It is sometimes used vaguely to refer to times of many millions of years, sometimes specifically referring to the dated occurrences of various geologic events or eras. |
b. Of persons: Fond of geology.
| 1854 H. Miller Sch. & Schm. (1858) 526 It was often explored by geologic tourists. |
2. transf. with reference to bodies analogous to the earth.
| 1868 Lockyer Guillemin's Heavens 153 These singular markings date from the last period of geologic change on the lunar surface. |