Scientists are examining different sea floor structures like those in the model of the Earth's crust below.

Question

The distance between X and Y represents thousands of kilometers of distance on Earth. The scientists notice that the rocks located at point X are older than the rocks located at point Y. What does this information about the age of the rocks indicate to the scientists?
A.
The sea floor is moving from Y to X over the course of millions of years.
B.
There is an underwater volcano producing new rock at point X.
C.
New rock is constantly covering old rock on the ocean floor.
D.
The sea floor is moving from X to Y over the course of millions of years.

Answer 1

The correct answer is D. The sea floor is moving from X to Y over the course of millions of years.

The observation that the rocks at point X are older than those at point Y suggests that new oceanic crust is being formed at point Y (possibly at a mid-ocean ridge or volcanic activity) and pushing the older crust towards point X. This is consistent with the theory of plate tectonics, where tectonic plates move apart, and new material is created at spreading centers, resulting in older rocks being further away from these hotspots.