Morrison Formation exhibits volcanic ash that flowed as a mud crossing Colorado, Eastern Utah, most of New Mexico, Wyoming, Montana, western half of North Dakota and South Dakota and Nebraska, and the north west corner of Kansas. This volcanic ash sediment laid down by volcanic activity and water contains materials mixed together which all came from varied environments: marine, terrestrial, mountainous, and coastal. This massive deposit is not a record of a series of violence over millions of years but a clear record of on massive and catastrophic event that took place in a relatively short time. This evidence serves as a snap shot of a massive burial of life in one sudden occurrence.
https://answersingenesis.org/fossils/dinosaur-national-monument-in-utah/
