Question 1
Zircons found in continental rocks give evidence that continental crust was forming as long ago as ________.
◦ 1.9 billion years ago
◦ 10,000 years ago
◦ 564 million years ago
◦ 70 million years ago
◦ 4.4 billion years ago
Question 2
One significant difference between oceanic and continental crust in terms of the long term evolution of Earth's surface is that ________.
◦ oceanic crust preserves a history of ancient deformation better than continental crust
◦ continental crust is harder to subduct than oceanic crust
◦ oceanic crust is less dense than continental crust
◦ oceanic crust contains more radioactive elements that contribute to the heating of the earth
◦ continental crust is more uniform in composition than oceanic crust