Posts Tagged ‘igneous’
What types of intrusive igneous rocks are formed by metamorphic rocks melting into magma?
So when a metamorphic rock is pushed into the earth’s surface, what kinds of intrusive igneous rocks can be formed when the metamorphic rock melts into magma?
What criteria is generally used to distinguish extrusive from intrusive igneous rocks?
The color of the rocks. Intrusive rocks are generally much darker in color than the extrusive rocks.
Visual acuity. If you can see the crystals with the unaided eye it is considered intrusive.
Their composition. Extrusive igneous rocks are richer in Si, Al, K and Na.
Xenoliths, if an igneous rocks contains xenoliths it is considered to be intrusive.