Tuff forms when some combination of ash, rock and mineral fragments (pyroclastics or tephra) are blasted into the air, then fall to the ground as a mixed deposit. Most of the rock fragments tend to be volcanic rocks that were once solidified parts of the volcano that erupted to produce the tuff, but sometimes other types of rock are blasted out and incorporated into the tuff as well. Sometimes erupted material is so hot when it reaches the ground that it fuses together to produce a welded tuff.
Related category GEOLOGY AND PLANETARY SCIENCE
Home • About • Copyright © The Worlds of David Darling • Encyclopedia of Alternative Energy • Contact