Question

question 6 4 pts the index fossil of a type of trilobite is discovered in layer a of a set of rock layers found at three different sites of field investigation. which conclusion can be made about the age of the rocks in layer a at all three sites? the rocks were formed by melting magma. the rocks are all different ages. the rocks are all the same ages. the rocks were formed during a catastrophic event.

Explanation:

Index fossils are defined as fossils of organisms that lived for a short, well-defined geologic time period, so their presence in rock layers across different locations indicates those layers formed during the same time span. The other options are incorrect: the question does not indicate igneous formation from magma, index fossils confirm matching ages not different ones, and there is no evidence of a catastrophic event.

Answer:

The rocks are all the same ages.