autoclasticadj.
/ˌɔːtə(ʊ)ˈklastɪk/, U.S. /ˌɔdəˈklæstɪk/, /ˌɔdoʊˈklæstɪk/, /ˌɑdəˈklæstɪk/, /ˌɑdoʊˈklæstɪk/ Geology.
Of a rock or its structure: consisting of fragments produced in situ by crushing or granulation.
ΘΚΠ
the world > the earth > structure of the earth > constituent materials > rock > composite rock > [adjective] > fragmentary
fragmentary1832
pyroclastic1862
clastic1877
fragmental1882
cataclastic1887
autoclastic1891
siliciclastic1961
volcaniclastic1961
1891 H. L. Smyth in Amer. Jrnl. Sci. 42 331 The two orotechnic actions have produced great developments of autoclastic schists. That is, schists formed in place from massive rocks by crushing and squeezing, without intervening processes of disintegration or erosion, removal and deposition.
1903 G. W. Lamplugh Geol. Isle of Man 70 The autoclastic structure occurs where strata of different characters are in juxtaposition.
1936 Geogr. Jrnl. 87 431 The base of the cliffs is formed by an autoclastic breccia dipping steeply east-south-east.
2003 M. G. Best Igneous & Metamorphic Petrol. (ed. 2) vii. 169/2 The base of the lava flow becomes autoclastic as well.
This entry has been updated (OED Third Edition, June 2011; most recently modified version published online December 2021).
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adj.1891