circa 5600 BC – According to the Black Sea deluge theory, the Black Sea floods with salt water. Some 3000 cubic miles (12,500 km³) of salt water is added, significantly expanding it and transforming it from a fresh-water landlocked lake into a salt water sea.
September 1, 5509 BC – day of creation of the world (according to the Byzantine Empire) and beginning of their calendar [1]
12,000,000 BC A natural deposit of cement compounds forms due to the reactions between limestone and oil shale during spontaneous combustion near present-day Israel.
5600BC The first concrete structures were built.
3000 BC The Egyptians began to use mud mixed with straw to bind dried bricks.