Answer:
ash-fall fossil formatin is very unique in its formation. 1. a volcano erupts, and ash is spread through the area. 2. an animal breathes in ash and dies. the animal is covered in ash. 3. soft tissues start to decompose as more ash starts to pile. 4. more ash continues to pile on top of the dead animal, and it turns to a rock. if this isn't very accurate go to www-museum.unl.edu/research/vertpaleo/ashfall.HTML
fyi this website doesnt work