Ancient Seawater

Scientists find an ancient pocket of seawater in the Chesapeake Bay that's 100-150 million years old

Results from more testing showed the water was twice as salty as today’s ocean water. When they analyzed its chemistry, they found high levels of chloride and bromide, the fingerprint of sea­water from another time, [USGS hydrologist Ward] Sanford said.

More tests and digging through research established that the chemistry was consistent with the “vast halite deposits created during the Jurassic and Cretaceous periods in the Gulf of Mexico and South Atlantic Basins,” the research paper said.