Simplify the following text for a Grade 12 native English-speaking person.
Original: Welded ignimbrites can be highly voluminous , such as the Lava Creek Tuff erupted from Yellowstone Caldera in Wyoming 640,000 years ago .
Simplified: A hot lava flow welded by heat can be highly voluminous , such as the Lava Creek Tuff erupted from Yellowstone Caldera in Wyoming 640,000 years ago .