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).
A: Index fossils are fossils that are found often in many different areas of the world. These types of fossils help to date other fossils that have been found in the same sedimentary layer of the Earth. Index fossils are also known as indicator or zone fossils since scientists and archaeologists use them to identify geological periods and stages. They work on the notion that if one type of species lived on Earth during one time period, and if a fossil of said species is found in many different areas, it must be from the same geological area.