Definition of ultrabasic in English:

ultrabasic

Line breaks: ultra|basic
Pronunciation: /ˌʌltrəˈbɛɪsɪk
 
/

adjective

Geology
  • Relating to or denoting igneous rocks having a silica content less than 45 per cent by weight.
    More example sentences
    • Major shear zones containing basic and ultrabasic igneous rocks are interpreted as suture zones.
    • This convergence gave rise to southward thrusting of the Yixieke forearc in Ordovician-Early Silurian time, which then led to obduction of the Buziwan ultrabasic rocks southward over the Kudi terrane.
    • On the other hand, the Kudi gneisses are imbricated with an ophiolitic slice south to Kudi, and overthrust by the Buziwan ultrabasic rocks.

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