Calcite is very near saturation in sea water and so is used as shells material by marine organisms. Canon de Huasteco near Monterrey, Mexico. Here in the Sierra Madre Orientale, there is more than 15km of carbonate sediments. Tectonically tilted to near vertical, they are resistant to weathering in the arid climate. The large cave entrance in the middle of the cliff face is characteristic of carbonates.
Evaporites are the rocks formed by chemical precipitation during evaporation of sea water.
Here alteration in the oxidation potential changes the color of Fe-bearing sediments from greeen to red resulting in prominent bedding visible in this outcrop. Bedding is a series of visible layers within the rock. It is primarily due to episodic nature of sedimentation where very fine particles are laid down slowly between times of more rapid deposition. Bedding planes are assumed to be originally horizontal or nearly horizontal for water-laid sediments. Mud-cracks can be preserved and indicate a depositional environment that is near shore and periodically exposed to air.