As a kid, I used to cycle out to our local volcano (albeit a Devonian felsite intrusion : Tinto Hill ) and explore an ‘Iron Age’ hillfort on its flanks. Its inhabitants were probably among the first to benefit directly from the fabulous geological diversity of the Scottish Midland Valley.
(Image from the Geological Society of Glasgow.)
So, as a consequence of geology, I grew up just a few miles from my nearest coal mine, steelworks; sand and gravel quarries, and just over 20 miles from the Leadhills where over 70 different minerals can be found (including gold!). All that made last week’s news that the very last remnants of the Scottish steel industry were ‘under threat’ all the more poignant. The cold winds of the 1984-85 miner’s strike whip through my memories of secondary school; the towers of Ravenscraig happened to come down when I was home on a visit during my PhD.
When these rocks were laid down Scotland benefited from an arid- equatorial climate and the Midland Valley was filled with restricted swampy shallow tropical seas or lakes in a complex ‘graben’ that provided the lithospheric stretching that allowed for occasional activation of volcanic centres. Rivers flowed from the Highlands into the valley.
These provided the perfect conditions for producing sediments rich in iron-ore and coal beds that provided the ‘heat’ to smelt them.
Ever since the Iron Age we’ve been enjoying these riches, in the 19th Century industry flourished as Scottish ‘pig-iron’ was smelted by Scottish coal to fuel the building of railways and ships. Scientists contributed ideas that refined and improved these processes and Scotland was an ‘early adopter’ of new ideas. In 1869 David Bremner wrote
“The blast furnaces are chiefly concentrated in the vicinity of Coatbridge, Airdrie, and Wishaw, all of which towns were rapidly raised to importance by the development of the mineral treasures which lay beneath and around them…..’
In the late 1800s Coatbridge and its iron generation was usurped by the ‘Steelopolis’ of Motherwell. Soon, the dark clouds of market forces (cheaper materials elsewhere) and politics arrived and so the long hard battles of the next century began.
To my young ear the disputes of the 80s, were complex and horrible: lack of coal could shut the furnaces down that were already under threat. I’ve linked to some resources that explore that. Its an important part of the pathway that has got us to where we are now.