sial

[sahy-al]
noun Geology.
  1. the assemblage of rocks, rich in silica and alumina, that comprise the continental portions of the upper layer of the earth's crust.
Compare sima1.

Origin of sial

1920–25; < German, equivalent to Si(licium) silicium + Al(uminium) aluminum
Related formssi·al·ic, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for sial

Historical Examples of sial


British Dictionary definitions for sial

sial

noun
  1. the silicon-rich and aluminium-rich rocks of the earth's continental upper crust, the most abundant individual rock being granite
Derived Formssialic (saɪˈælɪk), adjective

Word Origin for sial

C20: si (licon) + al (uminium)
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012