Lets say, one or two billion years ago.And what scientific evidence is there, to back up your statement ? P.S. Serious responses only please (unless you want to display to the world and yourself, what a tiny, dysfunctional, brain you possess).
From the watershed that leads into the ocean. Rivers and creeks and such pick up mineral deposits from the ground, and deposit them into the ocean. salts in the ocean are a variety of dissolved minerals, not just sodium chloride. The oceans were probably salty when they originated, but not to the degree that they are today.
the evidence for salinity occurs directly in the nature of the sediments of that era. Chemical sediments are quite common (frequently iron-rich chemical sediments comprising siderite, magnetite, ankerite) along with all of the more normal calcite and dolomite carbonate sediments, so this is fairly good proof that the oceans had elevated salt contents. There is also evidence from fluid inclusions, tiny bubbles of water that get trapped in minerals during formation. But mostly, chemical considerations oblige a certain level of salinity, of chemical makeup of the oceans. Minerals that form from reaction with or directly from water will only form within fairly specific windows of compositions, so we can tell an awful lot about water chemistry from the mineralogy of sediments and of rocks weathered and altered by contact with sea water. Way back, earlier than you postulate, the ocean chemistry is more difficult to constrain because we have little rock to use as evidence. then you fall into a problem of exactly how did the water get there in the first place, and if the presumption is that it comes from exhalation of water resulting from volcanic activity, this tends to lead to the idea that sea water was actually more salty than now. The general thinking about ocean chemistry is that it is controlled (buffered) over the long term (order of 10 miillion years) by interaction of seawater with oceanic crust in areas with high heat flow (the water circulates through the crust in convection cells and has its chemistry altered to be in equilibrium with crust at moderate temperatures, 100-300 degrees C). if that helps.
