A foliated metamorphic rock forms when crystals ________________________________________________.
combine but do not form bands
400
What rock-forming process occurs when hot magma forces its way into rock?
contact metamorphism
500
Explain the rock cycle.
Interactions among Earth's water, air, and land causes rocks to change from one type to another. Igneous rock forms when magma and lava cools. Igneous rocks are broken down into sediments, compacted, and cemented and as time passes form into sedimentary rocks. Heat and pressure of the sedimentary rock forms a metamorphic rock. Metamorphic rock becomes an igneous rock when it is buried deep beneath Earth's surface and melts into magma.
500
What kind of composition does a rock that contains mostly pyroxene and olivine (very dark and green) contain?
ultramafic
500
Because of the way they form, limestone and chert are classified as _______________ sedimentary rocks.
chemical
500
What two things can a metamorphic rock be classified by?
texture and composition
500
Define basaltic composition.
rocks with many dark silicate minerals and plagioclase feldspar (and are rich in the elements of magnesium and iron)