The Times of July 26th 1970 reported on findings by a group of French oceanographers, and this was that the Atlantic was much smaller in the Jurassic period, 160 million years ago. This is concomitant with continental drift, plate tectonics, and even with the expanding earth theory – so no surprise to a geologist. However, they added – conditions in the embryo Atlantic were similar to those of the Dead Sea in the modern world. It was salty. We may also note the Dead Sea is situated along the Rift Valley system that runs through Africa and the Levant. Presumably, the nascent Atlantic was also situated on a Rift system – and expanded from that point into an ocean (given enough time). It seems that rock salt exists at several locations around the Atlantic ocean boundaries – and was found in the 1960s in the Gulf of Mexico. In the Atlantic the salt forms domes – at the margins of the continental shelf (in Labrador and Newfoundland on one side and off the coasts of Morocco and Portugal on the other side). The scientists of the day concluded the salt was laid down when conditions in the Atlantic were much like the modern salt rich Dead Sea – but is rock salt being formed there?
All this is a bit bemusing and presumably the origin of rock salt now has a more refined explanation as southern Britain in the Jurassic is generally regarded as being submerged – and in a semi tropical environment on the fringes. That would imply the Atlantic was not quite as small as the French oceanographers thought.
There is of course another of looking at this – through the lens of catastrophism. The evidence of Jurassic marine life seen in the extensive clay formations that run across southern Britain and various parts of the European continent may not be due to submergence. It could be that the clay was laid down by water overspilling the continental land surface (bringing the marine animals with it and therefore preserving their fossils in the clay formation – or those life forms it swept up). Floods, even marine inundations on multiple occasions (rather than a Biblical diet of one or two) are currently unspeakable concepts (earning the disapproval of the uniformitarian mainstream). Of course, that still leaves the question of the salt – mainstream or off beam. How did it originate?