Question

Although the Earth's crust formed relatively early in the Earth's history, it was not present when the Earth first began to form. Also, plate tectonics has recycled the Earth's crust throughout most of its history.

Using this information, what can be concluded about the age of the Earth if the oldest known rocks in the Earth's crust are 4.28 billion years old?

A. The Earth is exactly 4.28 million years old.
B. The Earth is younger than 4.28 billion years.
C. The Earth is older than 4.28 billion years.

Answer 1

The Earth is older than 4.28 billion years.

"When the Earth first began to form, it was molten and did not have a crust. The crust formed sometime after the Earth formed as a whole. Therefore, the Earth's oldest known crustal rocks are not as old as the Earth itself. Also, because the crust has been recycled continuously through plate tectonics, these rocks may not represent the true, original crust of the Earth. This would be mean that the original crust is even older than 4.28 billion years.

Based on all of this information, it can be concluded that the Earth is older than 4.28 billion years."

Answer 2

The Earth is older than 4.28 billion years