Ancient seawater was recently discovered near Cape Charles, VA. Scientists, drilling approximately a half mile below the water's surface to explore a 56-mile crater at the mouth of the Bay, found trapped water that is nearly twice the salinity of today's seawater. The ancient water is thought to be between 100 and 150 million years old and a remnant of Early Cretaceous North Atlantic Sea water. A November 17 Washington Post article states in part:
The Chesapeake Bay Impact Crater was discovered in 1999 by a tandem of USGS and Virginia Department of Environmental Quality scientists. They theorized that a huge rock or chunk of ice slammed into an ancient ocean, sending enormous pieces of debris skyward and forcing monster tsunamis hundreds of miles inland...Over centuries, the crater became hidden under 400 to 1,200 feet of sand, silt and clay, hampering its discovery for decades..."It’s the largest crater discovered so far in the United States, and it’s one of only a few oceanic impact craters that have been documented worldwide,” USGS hydrologist David Powars said at the time.
Read the article in its entirety at washingtonpost.com or check out the USGS press release. The full study was published in the November 14, 2013 issue of Nature.