Faults in a plate are usually parallel to each other. They run up and down the plate in an area called a fault zone. Many people in the United States think of California when they think of faults. That's because areas with a lot of faults have a lot of earthquakes. In reality, there are faults all over North America, not just in California. Those fault zones may only be a few inches long or they can travel for miles without ending. There are two big types of faults: dip slips and strike slips .
A strike slip happens when two pieces of land move horizontally (side to side) to each other. That movement would be left or right compared to the other piece. We talked about California before. The San Andreas Fault in California is an example of a large strike slip. It is the point where the Pacific Plate and the North American Plate move against each other.
Silica-rich lava hardens before flowing far, forming a dense-texture rock of tiny crystals or glass . Basic lava flows further before it solidifies, giving rise to coarse-grained igneous rock, such as granite or gabbro . In many eruptions, lava is ejected with such force that it fragments in the atmosphere, hardens while airborne, and lands to form thick layers of volcanic tuff and related pyroclastic rock.