GEOL 101 Lecture Notes - Lecture 4: Igneous Rock, Swiss Cheese, Mafic
Document Summary
Explain the difference between a mineral and a rock. Define igneous rock and how they are formed. Explain the difference between extrusive and intrusive igneous rocks. Using the color of a rock, categorize an igneous rock"s composition. Discuss the differences between felsic, intermediate, and mafic. Explain how magmas evolve chemically and discuss bowen"s reaction series. Rocks: well consolidated aggregates of one/more minerals. Igneous: rocks that are formed by solidification of molten rock (magma or lava) As liquid cools, it crystallizes and forms well consolidated network of minerals (a rock!) Magma: partially molten rock, below earth"s surface. Extrusive (volcanic): igneous rocks formed when lava solidifies at earth"s surface. Intrusive (plutonic): igneous rocks formed when magma solidifies within earth"s surface. Texture: overall size, shape, arrangement of minerals. Rate of cooling is an important factor that contributes to texture. Porphyrite: mix of large and small crystals. When environment changes from slow cooling to fast cooling.
