Why are index fossils useful to geologists?
A. They tell the age of the rock at one location only.
B. They tell the absolute age of the rock in which they occur.
C. They tell the relative age of the rock in which they occur.
D. They tell the ages of many different rock layers.
I think it's D
because Index fossils are used by both geologists and paleontologists to study the rocks and species of the past. They help to give a relative age for the rock layers and other fossils found in the same layer.
C. They tell the relative age of the rock in which they occur.
The correct answer is C. Index fossils are useful to geologists because they provide information about the relative age of the rock in which they are found.
Index fossils are fossils of organisms that were widespread but existed for a relatively short period of time. They are commonly used by geologists as markers or indicators of a specific time period. When geologists find index fossils in a rock layer, they can compare it to the known age of the fossil to determine the relative age of the rock layer. This helps them establish the relative sequence of events in the geological record.
To get the answer to this question, you can start by understanding the concept of index fossils. Then, you can eliminate the incorrect options. Option A is incorrect because index fossils do not provide information about the age of the rock at one location only. Option B is incorrect because index fossils do not provide the absolute age of the rocks. Option D is incorrect because index fossils do not tell the ages of many different rock layers, but rather provide information about the relative age of the rock in which they occur. Therefore, the correct answer is option C.