Editor's summary from the Nature journal: Geologists and oceanographers generally have to rely on indirect evidence from the analysis of solid materials in dee

Editor's summary from the Nature journal: Geologists and oceanographers generally have to rely on indirect evidence from the analysis of solid materials in deep sediment cores when estimating temperature and salinity levels of the ancient oceans. But now a team from the US Geological Survey has identified a body of underground water that is actually a remnant of a past ocean water, a body of Early Cretaceous North Atlantic sea water. Deep drilling at the site of the Chesapeake Bay impact crater has yielded groundwater with an isotope and chemical composition signature that together with model analysis suggests that it was trapped in the sediments before the impact occurred around 35 million years ago. The water may have lain undisturbed for much longer: it has an average salinity of about 70 parts per thousand, twice that of modern sea water, and is probably 100–145 million years old. http://www.nature.com/nature/journal/v503/n7475/full/nature12714.html http://www.nature.com/nature/journal/v503/n7475/full/nature1...