Load Casts

These irregular and unusual rocky surfaces form when layers of sand or silt are deposited on top of beds of mud. As the overlying sediments settle downward into the mud an irregular surface forms on the sole or underside of the sandy, overlying layers.

Bioturbation Structures

Organisms living on the shallow seafloor often left tracks, trials, burrows and other marking behind from their activities and movements in the bottom sediments. These markings are often preserved in the sediemnt when it later hardens into stone. Such examples can be found here in the Deadwood Formation.

Glauconite Mineralization

Glauconite is an iron-rich, blue-green mineral that encrusts many of the Deadwood rock fragments. It commonly forms in shallow marine environments thus providing a clue as to its origin.