Seawater dating back 100 million years reveals that the Atlantic Ocean was TWICE as salty when dinosaurs roamed the Earth

Water was discovered deep underground in Chesapeake Bay, in Virgina

While older water has been discovered, this water is now thought to be the oldest large body of water known on the planet

An ancient pocket of seawater has been discovered deep underground in Chesapeake Bay, Virginia, and provides hints at what the world's oceans were like during the time of the dinoaurs.



The sample is thought to be 100 to 150 million years old and suggests that the Atlantic was once twice as salty as it is now.

The water contains chloride and bromide as well as other chemicals which helped the scientists age it to the Early Cretaceous Period.

The water is thought to date back 150 million years, when the Acrocanthosaurus roamed Early Cretaceous North America (CGI of dinosaur, pictured)

THE CRETACEOUS PERIOD

The Cretaceous Period refers to the state of the Earth 142 million to 65 million years ago. It ended with the greatest mass extinction in history - the entire planet's dinosaurs died out. It is thought that a giant asteroid impact caused the mass extinction.

Prior to this, the Earth was warm with no ice caps at the poles.

Much of what we now know as dry land - such as southern England and the midwest of the USA was underwater, since sea levels reached their highest ever during this time.

The Atlantic Ocean grew much wider as North and South America drew apart from Europe and Africa.

The Indian Ocean was formed at this time, and the island that was India began its journey north towards Asia.

While older water has been discovered in Canada, the Chesapeake Bay water that sits more than half a mile underground is now thought to be the oldest large body of water known on the planet.



'Previous evidence for temperature and salinity levels of geologic-era oceans around the globe have been estimated indirectly from various types of evidence in deep sediment cores,' said Ward Sanford, a United States Geological Survey research hydrologist and lead author of the investigation.



'In contrast, our study identifies ancient seawater that remains in place in its geologic setting, enabling us to provide a direct estimate of its age and salinity.'



Scientists have described the finding as 'like a fly trapped in amber', which was trapped by the aid of a massive comet or meteorite impact that struck the area about 35 million years ago, creating Chesapeake Bay.



The largest crater discovered in the U.S., the Chesapeake Bay impact crater is one of only a few oceanic impact craters that have been documented worldwide.



The largest crater discovered in the U.S., the Chesapeake Bay impact crater is one of only a few oceanic impact craters that have been documented worldwide.

Scientists have described the finding as 'like a fly trapped in amber'. It is thought to have been trapped by the aid of impact of a massive meteorite (CGI pictured)

About 35 million years ago a huge rock or chunk of ice traveling through space blasted a 56-mile-wide hole in the shallow ocean floor near what is now the mouth of the Chesapeake Bay.



The force of the impact ejected enormous amounts of debris into the atmosphere and spawned a train of gigantic tsunamis that probably reached as far as the Blue Ridge Mountains, more than 110 miles away.



The impact of the comet or meteorite would have deformed and broken up the existing arrangement of aquifers - water bearing rocks - and confining units - layers of rock that restrict the flow of groundwater.



Virginia's 'inland saltwater wedge' is a well-known phenomenon that is thought to be related to the impact crater. The outer rim of the crater appears to coincide with the boundary separating salty and fresh groundwater.



'We knew from previous observations that there is deep groundwater in quite a few areas in the Atlantic Coastal Plain around the Chesapeake Bay that have salinities higher than seawater,' said Jerad Bales, acting USGS Associate Director for Water.



'Various theories related to the crater impact have been developed to explain the origin of this high salinity. But, up to this point, no one thought that this was North Atlantic Ocean water that had essentially been in place for about 100 million years.'



'This study gives us confidence that we are working directly with seawater that dates far back in Earth’s history,' Bales continued.



'The study also has heightened our understanding of the geologic context of the Chesapeake Bay region as it relates to improving our understanding of hydrology in the region.'