[UP- 2.]
1. Geol. The action of raising, or fact of being raised, above the original level, esp. by volcanic action.
1838. Lyell, Man. Geol., v. 96. Very extensive regions … have been undergoing slow and gradual upheaval.
1862. G. P. Scrope, Volcanoes, 429. The upheaval of the latter strata.
1886. Winchell, Walks Geol. Field, 112. This is the general plan of a mountain of upheaval.
b. An instance of this; an upward displacement of some part of the earth’s crust.
1849. Dana, Geol., xvii. (1850), 675. Some of the upheavals the country has experienced, may have opened fissures.
1876. Page, Adv. Text-bk. Geol., ii. 39. Upheavals and subsidences occasioned by … volcanic convulsions.
1897. E. W. B. Nicholson, Golspie, 252. These upheavals took place after the separation from Norway and after the great Ice Age.
c. In general use.
1890. Clark Russell, Ocean Trag., III. xxviii. 74. A volcanic upheaval of flame.
1908. S. E. White, Riverman, iv. Constantly the logs shifted, and … the men shifted also, avoiding the upheavals.
2. fig. A strong agitation or convulsion of society, etc.; a sudden or violent alteration.
1825. J. Quincy, Life J. Quincy, Jun., 78. It was one of those popular upheavals, which, like a storm, sweep over a place to purify its atmosphere.
1850. McCosh, Div. Govt., II. iii. 250. There have been times of upheaval in the moral world, similar to those periods which geologists describe.
1867. C. H. Pearson, Hist. Eng., I. 89. It was a general upheaval of peoples.
1887. Lowell, Democr., 13. There had also been social upheavals before the Reformation.
Hence Upheavalist, an advocate of the theory that geological changes are due to upheaval.
1859. G. P. Scrope, in Q. Jrnl. Geol. Soc., XV. 519. It seems indeed strange that the upheavalist should fail to perceive that his own arguments and illustrations tell strongly against his own theory. Ibid. (1862), Volcanoes, 201. Sir. C. Lyell, in his elaborate and careful examination of this question, decided it against the upheavalists.
