In article ,
Rusty Hinge wrote:
The message
from (Nick Maclaren) contains these words:

The tens of thousands of years that's been there, any salt would have
been leached out, whatever the source.

If it was on the surface, yes. But there is a lot of salt underneath
Cheshire, that has not leached in millions of years. I could very
easily believe that many such deposits are mixtures of sand and salt,
and that there are places where salty sand is an accessible mineral
(and not near a current seashore).

I don't think sand at that depth would remain in free granular form, but
would be sandstone by now.

Not necessarily. To create sandstone, the pressure and temperature
has to be high enough to liquify something to glue the grains
together.

That salt in Cheshire has been there for a very long time, isn't very
close to the surface, and is, IIRC, sandwiched between two impervious
layers of rock.

Yes.

So much sand lies at the surface that no-one is going to mine the stuff,
anyway.

I was thinking of the (fairly common) circumstance where something
else (like salt) is mined, and the sand is a waste product.


Regards,
Nick Maclaren.