Creationists especially like to insist that a single cataclysm--Noah's flood--is responsible for most of the sedimentary deposits around the globe. They are quick to point to rock formations that show signs of turbulent, violent, high-energy forces that we might associate with floods.
Often, these creationist examples are dead-on. There are lots of areas around the world that show signs of catastrophism. However, creationists like to pick and choose their data. They don't point out the endless supply of deposits that clearly attest to slow-moving rivers, quiet lakes, and non-water-based action like sandstorms.
The discovery announced today of three new dinosaurs from Australia provides just such an example. As I explain in a news article at Prehistoric Planet.com:
The meat-eater and one of the plant-eaters were found buried close together in what appears to have been an ox-bow lake. These types of lakes are associated with very slow-moving, meandering rivers in which an extremely arced bend of a river becomes cut-off from the rest of the flow, creating a curved lake. The other skeleton was found in what looks to have been the sandy bank of a gently-flowing river.
The fact that some rock layers were laid down quickly is no problem for evolutionists. We would expect that regional floods and fast-moving streams were at work in the past. Rock layers around the world were clearly the result of a combination of all kinds of depositional forces from fast moving floods, to slow, meandering rivers.
While evolutionists are honest about this assessment, young-earth creationists have a big problem explaining how in the middle of Noah's flood there could be deposits from a gently-flowing river and a quiet lake.