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sial Line breaks: sial
Pronunciation: /ˈsʌɪəl/

Definition of sial in English:


[mass noun] Geology , dated
The material of the upper or continental part of the earth’s crust, characterized as relatively light and rich in silica and alumina. Contrasted with sima.
Example sentences
  • The rocks found in the crust of the continents is called sial.
  • A mnemonic term derived from for silica, for alumina, and for magnesium, applied as a compositional term to a layer within the Earth that occupies a position intermediate between sial and sima.


1920s: from the initial letters of silica and alumina.

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