| 释义 |
exogenetic, a.|ˌɛksəʊdʒɪˈnɛtɪk|
[f. as exogenesis: see -genetic.]
Having an external cause or origin.
1. Med. Of a disease: having a cause outside the body.
1874Dunglison Dict. Med. Sci. (new ed.) 385/2 Exogenetic, having an origin from external causes, as exogenetic diseases.
2. Geol.
a. Of rock: produced by the action of forces external to the material from which it was formed.
1904A. W. Grabau in Amer. Geologist Apr. 229 Contrasted with this group is that of the clastic rocks... These owe their origin chiefly to agents acting from without, and hence may be termed exogenetic. 1957F. J. Pettijohn Sedimentary Rocks (ed. 2) i. 4 It is desirable to discuss the textures of the exogenetic (clastic) rocks, the endogenetic (chemical) rocks, and the epigenetic (diagenetic) rocks separately.
b. Of rock or processes affecting rocks and landforms: formed or occurring at the surface of the earth.
1914T. Crook in Mineral. Mag. XVII. 72 The terms ‘endogene’ and ‘exogene’ have long been used by German and French geologists, chiefly as the equivalents of ‘eruptive’ and ‘sedimentary’... It seems permissible to use them as here required, in the forms endogenetic and exogenetic. Ibid. 73 Exogenetic processes are best subdivided..with reference to..weathering and denudation... Exogenetic rocks..are formed at ordinary or comparatively low tempertures. 1937Wooldridge & Morgan Physical Basis Geogr. v. 54 Exogenetic forces co-operate in all cases with the forces of upheaval. 1961L. D. Stamp Gloss. Geogr. Terms 184/1 Exogenetic is the usual English form, Exogenic..the American. 1970H. H. Read Rutley's Elem. Mineral. (ed. 26) i. v. 212 Exogenetic deposits are due to surface-processes such as deposition in a salt-lake or sorting by river-action. |