Some of them are burried well deep down there. How did it happen?
What about TimeTeam digging up viking villages in Cumbria? They're 10ft deep and are only 1000 years old. How did 1000yr old shit get 10ft under ground?
The viking villages were just simple sedimentary deposition. Deposition rates vary with time and location.
The dinosaurs were buried in a global flood about 4000 years ago.