请教：XDF教材上的一道题

readytosayno

Many geologists theorize that the trail of volcanic craters and cinder cones along the Snake River plain of southern Idaho was produced as the North American continent slid westward over a stationary "plume",a vertical channel through which molten rock rose intermittently from the Earth'cor to burst through its crust.

Which of the following ,if true ,tends to support the geologists' theory of how the trail was produced?

a)The largest craters and cinder cones are on the eastern margin of the trail

B)The most violent volcanic activity apparently occurred at the western margin of the trail.

C)The newest craters and cinder cones are on the eastern margin of the trail.

D)The craters and cinder cones are evenly spaced throughout the extent of the trail.

E)The craters and cinder cones on the western margin of the trail generally took longer to from than did those on the eastern margin.

the answer is C ,why ?thanks !

lugubrious

那个地球板块向西那个漂，有个固定的地方，从地球里边向外冒岩浆什么的。

那么在这个板块的西边的什么那些和火山，岩浆有关的东西肯定先形成，东边的就后形成了。