There is a good book called “Chesapeake Invader” by C. Wylie Poag that tells the story of the discovery and study of the 35 million year old impact that created the conditions that may have preserved the even older salt water found and reported in this article. I always though it was cool that a large asteroid impact, not to far south of me, may have created the Chesapeake Bay. The book talks about how the ground in that area is so disturbed from the impact that when drilling you are never sure if you will hit a freshwater or saltwater aquifer, which is a problem if you want to drink or irrigate with it.
