The Landscape
Lochs and islands, sea-lochs and mountains – yes, our area has it all. How did it all happen? Why are there so many fine views, interesting walks and soaring hills?
Well, it’s all to do with a landscaping company. Let’s call it Ice Age Glaciers Ltd. They had lots of time and lots of heavy ice as their main kit. And they were still working on the Loch Lomond landscaping project about 10,000 years ago (though they’d been at it, off and on, for millions of years before that). They came up with some pretty good landscape designs.
To find out more, let's take a walk above Loch Lomond
A walk about Loch Lomond
Beyond the little power station at Inveruglas (on Loch Lomond between Tarbet and Ardlui) you can park at a very pleasant viewpoint on the shore, then walk back a short way to find a little road that leads west, eventually heading for the Loch Sloy dam. Stroll up this and enjoy some very fine hill scenery, dominated by the high peaks of Ben Vorlich and Ben Vane.
As you walk uphill, away from Loch Lomond, up the Inveruglas Water, you are in a kind of a glen which geologists call a 'hanging valley'. If you look back, across Loch Lomond to Inversnaid, you will see that, like Inveruglas, it also sits below a hanging valley – one that holds Loch Arklet, higher up and at right angles to the main deep valley filled by Loch Lomond. It’s a matching pair of hanging valleys on either side of the loch. From this you may think that there is some connection.
Well, there used to be. Before Loch Lomond, a great river once flowed east from the area around Loch Sloy, across the glen in which Loch Arklet sits, then down by Loch Katrine and on south-east into the Lowlands. But this changed when Ice Age Glaciers got to work. They decided that we should have the largest loch in Scotland right here.
So they cut a trench, right across the old river, and much deeper. After it was filled, we called it Loch Lomond. The old landscapes were changed completely.
Caution - glaciers at work
But Ice Age Glaciers hadn’t finished yet. They did the same trick further south on the loch. Both Glen Douglas and Glen Luss were part of another river system flowing eastwards towards today's River Endrick and on towards Strathblane and, eventually, the River Forth. But the cutting of the Loch Lomond trench changed things. Now the little Luss Water enters the loch by the attractive village of the same name.
Loch Lomond – two lochs in one
Even glaciers have to start somewhere. Ours was just one of many that trundled down from a great ice sheet in the vicinity of today's Rannoch Moor. It was determined to create a loch worthy of a well-known song. First of all, there was a backdrop to make, so that visitors could have a spectacular background to their photographs. So the Arrochar Alps were scoured and sharpened. This was a tough job, as the rocks here are hard. (Geologists call them diorites.)
In fact, hard rocks made the Loch Lomond trench pretty narrow. So, grinding slowly southwards, it must have been a relief to get over the Highland Boundary Fault at Balmaha where the glacier could spread out and shift a lot of much softer rock. That’s why Loch Lomond is so much wider at its south end. It’s not in the Highlands. Here, around Balloch or Gartocharn, it’s a Lowland loch.
Where will we put all this rock? All around Balloch?
In any landscaping project you’ve got to dispose of stuff. Ice Age Glaciers had a great idea – they decided to dump all the rocks and gravels, collected in the north, at the south end of Loch Lomond. This was right at the end of the project, about 10,000 years ago. Otherwise Loch Lomond would have been a sea-loch, like Loch Long is today. (At one time in its glacier story, Loch Lomond actually was a sea-loch - though sea-anglers were scarce in those days.)
So Loch Lomond was effectively dammed by the glacial spoil – and it is only 27 ft (8m) above sea level. All this means is that, on a geological time-scale, the 'Bonnie, bonnie banks' were created just the other day – as the last job undertaken by Scotland’s Ice Age Glaciers. That company isn’t around any more. It just got too hot for them.
