Question

Use the diagram to answer the question.

Information
The diagram shows layered rocks. Four layers are stacked from top to bottom: 1, 2, 3, and 4. A fifth layer is labeled X; it intrudes layers 1 through 4.

Question
What is the relative age of the rocks in the intrusion marked by X?

Answer options with 5 options
A.
The rocks at X are the oldest.

B.
The rocks at X are the youngest.

C.
The rocks at X are older than layer 4 but younger than layer 3.

D.
The rocks at X are older than layer 2 but younger than layer 1.

E.
The rocks at X are older than layer 3 but younger than layer 2.

Answer 1

In geological terms, an intrusion is a body of rock that forms from the cooling and solidification of magma beneath the Earth's surface. When an intrusion occurs, it cuts through existing layers of rock.

Based on the information provided, the layers are stacked in the order from oldest at the bottom to youngest at the top: Layer 4 is the oldest, and Layer 1 is the youngest. Since the intrusion labeled X cuts through layers 1, 2, 3, and 4, it must be younger than all of these layers.

Therefore, the rocks in the intrusion marked by X are the youngest.

The correct answer is:

B. The rocks at X are the youngest.