As soon as rock starts melting ... pockets to deeper reservoirs of molten basalt. Magma made of rhyolite produces characteristic volcanic ash, but basalt is the real driver of eruptions because ...

A new volcanic vent was discovered at Yellowstone National Park, the U.S. Geological Survey announced this week.

If you are planning on driving in Yellowstone National Park when most of its roads open in April, you could drive by one of ...

According to the Yellowstone Volcano Observatory, it’s probable that this new hydrothermal feature is connected to activity ...

It's a volcanic (igneous) rock resulting from cooled lava with a low amount of silica. It's often black or dark gray and used in floor tiles or cobblestones. Rhyolite is another volcanic rock ...

A park scientist noticed it about two weeks after a hydrothermal explosion along a boardwalk during the park’s overactive ...

Volcanic rock and volcanic glass are formed when lava cools ... Generally, these rocks (granite and rhyolite) are light in color, and their density is relatively low. The feldspar predominates in ...