Question

Geologists found fossils in several layers within the Earth and have determined, by using C-14 dating, that of all of the following layers of fossils found in the illustrated rock layers the fossils found in layer ________ are the oldest.

Answer 1

mantle layer is the answer

Answer 2

Answer

In the rock layers, the fossils found in deepest layers/mantle are the oldest.

Explanation

Geological column showing rock layers is an evidence used by geologist to determine the older and younger fossils. The deeper we dig , the farther back in time we see. The oldest fossils are found at the deepest layers and the youngest  are at the top.