Most surface rocks on Earth are younger than a few million years old, whereas ages of lunar rocks have been measured in billions of years. Why?
A) Much of Earth's surface is continually recycled (created and subducted) by the underlying mantle because of plate tectonic activity; this process does not occur on the Moon.
B) Most early surface rocks on Earth have been washed into the sea by weathering and rainwater; this process does not happen on the Moon.
C) The complete surface of Earth has been covered periodically by younger material from intense volcanic eruptions in the last few million years; no such activity occurred on the Moon.
D) The ages of Earth and the Moon are fundamentally different; the Moon is an old object captured from space by a younger Earth.

Question

Quizplus · Accepted Answer

Much of Earth's surface undergoes a continuous cycle of creation and destruction due to plate tectonics, a process absent on the Moon, leading to younger surface rocks on Earth compared to the older lunar rocks.

Most Surface Rocks on Earth Are Younger Than a Few