from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun Any of a series of igneous rocks similar in composition to basalt but having more silica and iron and less aluminum.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun geology An
igneousbasaltic rock, formed from magmarich in magnesiumand iron.
from The American Heritage® Dictionary of the English Language, 4th Edition
from Wiktionary, Creative Commons Attribution/Share-Alike License
The coastline is also cut through by olivine and tholeiite dykes, a good example of which can be seen at Roveran Valley Head.
Myles L. Miller, Scott S. Hughes, 2009, Mixing primitive and evolved olivine tholeiite magmas in the Eastern Snake River Plain, Idaho