How does tuff rock form from volcanic ash?

Tuff is a type of rock that forms when volcanic ash is ejected from a vent during an eruption and subsequently lithifies into solid rock. Rock that contains more than seventy-five percent ash is classified strictly as tuff. Although it is relatively soft and has been widely used in construction and sculpture across history, it can be studied under both igneous and sedimentary petrology.

What we know

• Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. [4]
• Following ejection and deposition, volcanic ash lithifies into solid rock to form tuff. [4]
• Rock that contains greater than seventy-five percent ash is considered tuff. [4]
• Tuff can be classified as either an igneous or a sedimentary rock and is studied by geologists examining formations like the Kneeling Nun Tuff. [2, 4]

Where to go next

• what caused itWhat is the Emory caldera?
• how it workedHow are supereruptions triggered?
• a case in pointWhat is the Bandelier Tuff?
• compared withHow do igneous and sedimentary rocks differ?
• an unexpected connectionWhat are moai statues made of?

Sources

• [1]Kneeling Nun Tuff (Wikidata Q108195930) · CC0 1.0
• [2]Kneeling Nun Tuff · CC BY-SA 4.0
• [3]Kapthurin Formation · CC BY-SA 4.0
• [4]Tuff · CC BY-SA 4.0
• [5]Bandelier Tuff · CC BY-SA 4.0