Which statement best describes the age of fossils deeper in rock layers compared to fossils higher up?

Which statement best describes the age of fossils deeper in rock layers compared to fossils higher up?

• A. They Are Generally Older
• B. They Are Generally Younger
• C. They Are the Same Age
• D. Age Cannot Be Determined

Answer: (A)

Fossil ages in layered rocks follow a simple sequence: sediments settle and form new layers on top of older ones. The bottom layer appears first, followed by layers on top, so the fossils in deeper layers lived earlier than those in higher layers. This idea, called the law of superposition, lets scientists read a history of life by looking at rock order. It works best when the rock hasn't been disturbed by folding, tilting, or erosion, which can mix the layers. So, fossils deeper in rock layers are generally older.

Fossil ages in layered rocks follow a simple sequence: sediments settle and form new layers on top of older ones. The bottom layer appears first, followed by layers on top, so the fossils in deeper layers lived earlier than those in higher layers. This idea, called the law of superposition, lets scientists read a history of life by looking at rock order. It works best when the rock hasn't been disturbed by folding, tilting, or erosion, which can mix the layers. So, fossils deeper in rock layers are generally older.