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).
fossils help geologists match rock layers it is widely distributed and represents an organism who only existed briefly it is helpful because they tell the relative age of the rock layers in which they occur. can scientists use the law of superposition to determine the absolute age of rocks.