Foliation & Lineation

This week I'll be heading out to do more research with Dr. Dinklage, this time out in the Pequop Mountains in Nevada. We will be working with more metamorphic rocks. One characteristic that some metamorphic rock may contain is foliation and lineation. They are defined as follows: Foliation - The arrangement of a set of minerals in parallel, sheet-like layers that lie perpendicular to the flattened plane of a rock. Occurs in metamorphic rocks on which directed pressure has been exerted. Lineation - Minerals that are linear or have been positioned or deformed in the same direction due to stress and strain. These characteristics occur because tremendous amounts of force deform the rocks during an orogeny, or mountain building. Heat and pressure are what determine how a rock will deform. It could become low grade (little metamorphism) to high grade (great metamorphism).