Mesozoic deposition in the Rockies occurred in a mix of marine, transitional, and continental environments as local relative sea levels changed.
In rock layers at this time, the earliest layers represent sea beds, later layers represented shorelines, and the latest represented continental environments.
Sandstone deposits are contained within medium to coarse-grained sandstones deposited in a continental fluvial or marginal marine sedimentary environment.
Terrigenous sediment supply to the deepwater bottom-currents and to the nepheloid layer primarily depends on climate and tectonics in the continental environment.
These islands are often quite large, and have most of the geographical features of the continental environment including beaches, reefs, lagoons and even estuaries.
Deposition took place in an arid, continental environment (playa facies), so that there was little chemical weathering.
However, a red colour does not necessarily mean the rock formed in a continental environment or arid climate.
Besides transport by water, sediment can in continental environments also be transported by wind or glaciers.
The stratigraphical beds were deposited in both continental and marine environments.
Apart from fossils, it shows many other signs of being deposited in a continental environment, such as mudcracks and -in some rare cases- dinosaur footprints.