The Cretaceous Period - Jurassic Coast

Early in the Cretaceous, the environment of the World Heritage Site was similar to the modern Gulf of Arabia, with lagoons covered by salt flats known as sabkhas.  

http://jurassiccoast.org/rocks-and-fossils/140-the-geology/381-the-cretaceous-period

During the Cretaceous Period the continents continued to spread apart. Repeating thin layers of limestone and clay form the Early Cretaceous show that conditions fluctuated between salt flats and lush swamps and lagoons. Dinosaurs roamed the salt flats while crocodiles hunted fish in the swamps.


http://jurassiccoast.org/rocks-and-fossils/a-super-continent-divides