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).
Index fossils. Radiometric dating. The Age of Dinosaurs was so many millions of years ago that it is very difficult to date exactly. Scientists use two kinds of dating techniques to work out the age of rocks and fossils. The first method is called relative dating.