Researchers have been studying a hot spot volcano in Samoa to learn about the composition of Earth's inner layers.  The magma that feeds hot spot volcanoes comes from much deeper in the mantle than the magma that erupts along plate boundaries.  For this reason, analyzing the materials found in the magma helps geologists understand more about what the hot, inaccessible inner parts of Earth are made of.  Getting a better picture of the Earth's mantle and core gives us clues about how the Earth formed, by showing us what elements were present as gravity first pulled chunks of matter together into the molten ball that eventually became our home.

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