This sequence of events would explain why any volcanic rocks that have erupted onto the surface in the past few billion years should still be unweathered and pristine.
这一连串事件可以解释，为什么过去数十亿年来，所有喷发到地表的火成岩仍然原始而未风化。
2
Beitai basin is a trapped syncline with its sedimentary sequence composed of volcanic sedimentary facies.
北台盆地为宽缓的向斜，盆地沉积充填序列为火山沉积序列。
3
A whirlwind computer animation sequence gives you a ride through the center of the earth to see the process of the geological forces that cause a volcanic eruption of earthquake.