the theory that the earth's crust was formed by volcanoes or the formation of plutons within the earth's crust
plutonism in American English
(ˈpluːtnˌɪzəm)
noun Geology
1.
the intrusion of magma and associated deep-seated processes within the earth's crust
2. (often cap)
the disproven theory that all rocks formed by solidification of a molten mass, promulgated by Scottish geologist James Hutton (1726–97)
Derived forms
plutonist
noun
Word origin
[1840–50; pluton(ic) + -ism]This word is first recorded in the period 1840–50. Other words that entered Englishat around the same time include: bypass, flan, layout, organizer, sensationalism-ism is a suffix appearing in loanwords from Greek, where it was used to form action nounsfrom verbs (baptism). On this model, -ism is used as a productive suffix in the formation of nouns denoting action or practice,state or condition, principles, doctrines, a usage or characteristic, devotion oradherence, etc. (criticism; barbarism; Darwinism; despotism; plagiarism; realism; witticism; intellectualism)