Question

A. Magma exists below Earth's crust.
B. Magma can push through holes or cracks in the crust.
C. All magma intrusions result in volcanoes on Earth's surface.
D. Layer A must exist at higher temperatures than the other layers.

According to the law of superposition, we can conclude that layer A in the diagram is the oldest layer. Based on the layers and structures seen here, we can draw additional conclusions. Review the prompt and select all that could apply.
Responses
A A and DA and D
B A, B, DA, B, D
C A and BA and B
D A, B, C, D

Answer 1

Answer: B (A, B, D)

Why:
- A is correct: magma exists beneath the crust (source for intrusions and eruptions).
- B is correct: magma can force its way through cracks or holes in the crust (forms dikes, sills, etc.).
- D is correct: if layer A is the lowest/oldest layer it is deeper and therefore generally at higher temperature (geothermal gradient).
- C is false: not all magma intrusions reach the surface—many intrusions cool and solidify underground without forming volcanoes.