Question

How are index fossils useful in determining geologic time

Answer 1

Step-by-step explanation:

Keyed to the overall time scale are instances of record fossils, the types of life which existed during restricted times of geologic time and in this way are utilized as advisers for the age of the stones in which they are safeguarded.

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Answer 2

Step-by-step explanation:

Keyed to the relative time scale are examples of index fossils, the forms of life which existed during limited periods of geologic time and thus are used as guides to the age of the rocks in which they are preserved.