Magma spends most of its existence as sludgy mush

Crystals open window into volcanic depths

UNDER THE VOLCANO  Mount Hood looms over Oregon’s White River Valley. A study of magma that poured into this valley around 220 years ago shows that the magma spent most of its long existence under the mountain in a cold, semisolid state.

Erik Klemetti

When red-hot magma spews from a volcano, it is clearly flowing like a liquid.