Salinity of the sea rules out a young Earth

[QED]

Sir Edmund Halley came up with a way to make an estimate of the Earth's age: He realized that as fresh water is deposited in form of rain, water picks up salts and other minerals from the land and deposits them in the sea. This is why lakes are largely fresh water and the sea is salty. Halley reasoned that in time the oceans should get more salty as the salt remains trapped in them by continual evaporation.

Rather than use this to arrive at a specific date, Halley was more interested in showing that the Earth could neither be infinitely old (as the sea would be saturated with salt) nor very young (a few thousand years) otherwise the oceans would still be mostly fresh water.

Using Halley's ideas, Irish geologist John Joly went on to compute an age for the Earth which came out at around 80 Million years; an underestimate as he assumed that all salt would remain dissolved in the Oceans which it does not. Nonetheless it does serve to show that the idea of a 6000 year old Earth is untenable: for the salinity to be at its current level, then his assumptions about the take-up of minerals would have to be over thirteen thousand times too conservative.

The logic of this argument would seem to be quite accessible to any reasonable person. Does anyone disagree that it would rule-out the Earth being less than millions of years old and if so for what reason?

[ConiectoErgoSum]

perhaps the earth popped into existence just yesterday, as did everyone's brains with the pre-fab memory of all things past, and the notion that the past even existed. Along with salty oceans. I mean shoot, given enough possible universes, could there not be one whose existence matches that described above?