The diagram above shows a stack of rock layers. Examine the diagram, and answer the question that follows. Layer T contains a well-known index fossil that is 120 million years old. Layer R contains a different index fossil that is 100 million years old. Based on this information and the principle of superposition, how old is Layer M?
(1 point)
Responses
younger than 100 million years.
younger than 100 million years.
either 20 million years or 220 million years.
either 20 million years or 220 million years.
older than 120 million years.
older than 120 million years.
between 100 million and 120 million years old.
Based on the principle of superposition, which states that younger layers of rock are deposited on top of older layers, we can conclude that Layer T is younger than Layer R. Since Layer T contains an index fossil that is 120 million years old and Layer R contains a different index fossil that is 100 million years old, we can infer that Layer T is younger than Layer R but older than 100 million years. Therefore, Layer M, which is below Layer T, would be older than 120 million years.
So, the correct answer is: older than 120 million years.