The focus is the place inside Earth's crust where an earthquake originates. The point on the Earth's surface directly above the focus is the epicenter. When energy is released at the focus, seismic waves travel outward from that point in all directions.
Roal Amunsen was the first.
Answer:
c. they form adjacent to an intruding pluton, which provides heat for metamorphism.
Explanation:
- In metamorphic rocks, the contact metamorphism produces the aureoles in the surrounding zones of the rocks that get altered.
- There varies in the thickness from the from centimeters to several kilometers like the large granitic intrusions and they typically consist of non foliated rocks formed due to the heat sources and intruding plutons.
