Rock Blobs

Science Daily: Giant Blobs of Rock, Deep Inside the Earth, Hold Important Clues About Our Planet

summary - Two massive blob-like structures lie deep within the Earth, roughly on opposite sides of the planet. The two structures, each the size of a continent and 100 times taller than Mount Everest, sit on the core, 1,800 miles deep, and about halfway to the center of the Earth. Researchers suggest these blobs are made of something different from the rest of Earth's mantle, and are determined to figure out what that is.