Approximately when did the earth's crust solidify?
A) 8 billion years ago
B) 4 billion years ago
C) 2 billion years ago
D) 1 billion years ago

Question

Quizplus · Accepted Answer

The Earth's crust solidified about 4 billion years ago, which is the best choice given. This process occurred after the initial accretion and differentiation of the planet, during which the heavier elements sank to form the mantle and core, leaving the lighter elements to form the crust. The first solid crust was likely quite thin and unstable, but eventually, as cooling continued and continents formed, it became more solid and stable over time.

Approximately When Did the Earth's Crust Solidify