Ancient Seawater Found... In America

Scientists have recently discovered an area of ancient, salty seawater near the mouth of the Chesapeake Bay. The patch of seawater was discovered in an attempt to map a freshwater aquifer 5,000 feet below the sea's surface. It has been trapped for as long as the earth has been dinosaur-less which gives proof that the Atlantic Ocean was once more salty than it currently is. Scientists are able to tell the age of the water by measuring the amount of helium in the water. (This helium is released as uranium decays.) When the water became trapped (about 100 million years ago) the Atlantic Ocean was much smaller and thus had a higher concentration of salt.