The story of the rock salt on our roads

Photo: The Salt Association

As we were eating our breakfast today, and I was driving J mad by asking what a tiger would do if it came across Molly (a much smaller and domesticated version of the species), the TV news channel was earnestly talking about salt and how councils are stocking up.


I was distracted from the tiger argument (much to J's relief) by the discovery that salt is bought from Egypt. I then Googled "wheere does road salt come from?" and it became one of those fascinating and immersing topics.

My mum, the Giz, was yesterday pricing bags of salt v grit in her local hardware store.

I discovered that rock salt has formed at various times in the geological past as a result of the drying up of the sea. The evaporating water left behind beds of sea-salt.   In northern Europe, thick deposits of rock salt were lain down during Permian imes (290 million years ago) across a wide area stretching from eastern England, under the North Sea eastwerds to the Netherlands, Germany, Denmark and Poland (Poland is famous for its salt mines).

In the UK, salt of Permian age is mined in Cleveland. Younger salt beds, of Triassic age (200-250 million years old) is mined from the Cheshire basin, Cumbria and northern Ireland.

Even more fascinating, rock salt mines have the right conditions to make excellent repositories for archive documents.

And the good news is, according to the Salt Association, we're not likely to run out of salt. The UK's salt mines have about 225km (140 miles) of tunnels - almost as long as the M5 motorway. And that's without turning to countries like Spain and Egypt for supplies. All we have to hope is that our councils have learned from the lessons of earlier this year and stocked up.