Sol definition, the syllable used for the fifth tone of a diatonic scale. See more.
Examples of index fossils. Index fossils (also known as guide fossils, indicator fossils or zone fossils) are fossils used to define and identify geologic periods (or faunal stages).
Best Answer: Index fossils are certain fossils that lived for a short period of time but covered a large area, so If you found an index fossil and knew the time period over which it lived that would be the same age of rock. Index fossils help correlate rock layers around the world.