It's been 35 million years since a large meteorite slammed into the Earth, cracking bedrock beneath what is now the Chesapeake Bay. The impact left pores that collected groundwater from beneath it. Now researchers have dated that water to between 100 million and 145 million years old, and report
that it's twice the salinity of modern sea water. Salinity levels of ancient oceans tend to be estimated indirectly from geochemical, isotopic and palaeontological analyses of solid materials in deep sediment cores. These analyses had hinted that groundwater beneath the Chesapeake was highly saline. Now for the first time scientists have extracted and tested the ancient water directly. They collected water from core samples taken from more than a mile deep by using a centrifuge to extract the liquid.
Chemical tests on the water indicated it had been undisturbed for 100-145 million years---making it a direct remnant of Early Cretaceous North ...
