WEATHERING AND EROSION OF BONES FROM THE AARON SCOTT DINOSAUR SITE NEAR FERRON, UTAH (MORRISON FORMATION, JURASSIC)

The Aaron Scott Site consists of an accumulation of vertebrate remains in the Jurassic Morrison Formation of central Utah that is dominated by a partially articulated skeleton of a sauropod. Surrounding it are disarticulated, fragmented remains of numerous animals including Allosaurus, Stegosaurus, Ceratosaurus, an ornithopod dinosaur, turtle, crocodile and sphenodonts.

The bones experienced a range of weathering. The weathering stages are broken into a range based on certain criteria: disarticulation, splintering, breaking and rounding of the edges. The range is used to rank the amount of weathering that has occurred to help determine the depositional environment.

The weathering stages seen here indicate that the bones were exposed on the surface and accumulated over a period of time. The orientation of the bones indicates a deltaic environment where animals accumulated during a drought, died and decomposed. They were then buried due to rising lake levels following the drought.

A bimodal distribution of all the bones recovered from the site indicates a primary influence from the current of a river channel and a secondary influence from wave action at the edge of a lake.