[editor-surveyor]

The salt in sea water likely got there 4500 years ago when the “fountains of the great deep” ruptured, bringing the salt to the surface.

Anyway, there is no basis for age determination by the presence of salt, unless you assume distilled water to start, and a constant rate of accretion,which is illogical on it’s face.

[ColdWater]

The salt in sea water likely got there 4500 years ago when the “fountains of the great deep” ruptured, bringing the salt to the surface.

So all previous fish were fresh water fish which would have resulted in mass death since they could not survive the rapid change.