Supersaline sediments off East Coast shed light on Atlantic Ocean’s early history
Water, water, everywhere and some of it’s been undisturbed for more than 100 million years.
Groundwater collected from sediments at the mouth of the Chesapeake Bay is thought to be 100 to 145 million years old. The ancient samples, twice as salty as modern seawater, were already trapped in sediments when an asteroid or comet landed in the area some 35 million years ago, researchers report in the Nov. 14 Nature.
Similarly salty waters in sediments off the Atlantic Coast of North Carolina, Georgia, Maryland and New Jersey could be just as old, but no one has sampled them carefully enough to find out, says Ward Sanford, a research hydrologist for the U.S. Geological Survey. Ten years ago, the USGS with the International Continental Scientific Drilling Program drilled a deep hole in the Chesapeake Bay impact crater to figure out how the 3-kilometer-wide asteroid strike had changed