Match the following. Match the items in the left column to the items in the right column. 1. correlation spectrometer semi-dark line that indicates the ridge of a fold on a geologic map 2. d**e location on the earth's surface directly over the focus of an earthquake 3. elastic rebound instrument used to measure volcanic gases 4. epicenter energy produced from the heat of magma and other volcanic materials 5. focus specific point in the earth where the rock layers along a fault move, producing an earthquake 6. fold axis block of rock below the slant of a fault 7. footwall shows locations and types of rocks and other features, like faults and folds 8. foreshocks vertical intrusion of magma between rock layers 9. geologic map immediate return of deformed rock to its natural shape 10. geothermal energy mini-quakes that usually occur before a major earthquake