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).
â¢ Fossils, ice cores, and tree rings. record conditions and changes. in the environment. NOW, you will learn. â¢What the relative ages of rock. layers reveal about Earth. â¢ How index fossils are used. to determine the ages of.