
http://www.kaibab.org http://vishnu.glg.nau.edu/rcb/Grand_Staircase.html/
The Grand Staircase is a presentation of the stratigraphy of the southern Colorado Plateau and Grand Canyon by Ron Blakey at Northern Arizona University.
http://walrus.wr.usgs.gov/docs/seds/sedimentology.html
The Bedform Sedimentology site of the United States Geological Survey (USGS) offers images and movies of cross-bedding and bedform features in sedimentary rocks.