Most volcanoes that occur in the interiors of plates are believed to be produced by mantle plumes, columns of molten rock that rise from deep within the mantle.
人们认为，大多数发生在板块内部的火山爆发都是由地幔柱造成的，地幔柱是指从地幔深处涌出的熔岩柱体。
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The plumes apparently originate at great depths, perhaps as deep as the boundary between the core and the mantle, and many have been active for a very long time.