Royal Grammar School


Geographical Time Lords

Geographical Time Lords

Sunday 8 June 2014: twelve Year 9 Geographers gathered evidence reaching back 350 million years. The time travel began, not by TARDIS but by minibus. Continuing on foot from Clapham Village near the North Yorkshire/Lancashire border, the group was soon amongst one of the best and most beautiful limestone landscapes in Europe.  

As the sun shone down on this 21st Century day, the rocks began to reveal the secrets of prehistoric time. Walking up Clapdale, a river valley without a river; scrambling up Trow Gill, a waterfall without water: evidence of a time 11,000 years ago, when ice had filled the joints and bedding planes, rendering the rock temporarily impermeable as torrents of glacial meltwater shaped the geomorphological features. Limestone pavements with their clints and grykes could only have formed if ice had stripped off the overlying regolith over a period of 100,000 years until about 9000BC. Then the spectacle of Gaping Gill: a hole in the ground, 10m in diameter with a chilling 100m vertical drop, swallowing the Fell Beck. Where had it gone?  

The group found it again a couple of kilometres down the valley surging out of a limestone cliff. It warranted further investigation. One kilometre inside the mountain and 80m deep, the dark and silent world of the cave threw up more geographical evidence. Stones rounded by attrition proved that the caverns were eroded by gushing underground rivers. Myriad fossils in the natural rock ceiling included 350 million-year-old tropical corals: evidence that the area developed beneath an ocean and of tectonic plate movement, for Yorkshire is neither under the sea nor experiencing a tropical climate now. In the sediment on the floor, the molar of a woolly mammoth had been found in 2011 and dated to 14,000 years ago. And climate change! Clearly the recovery from the Devensian ice age was suggested by the way landscape features had formed but what about recent global warming? The Victorians started a record of stalagmite growth in the cave, showing the average rate has been one-quarter of a millimetre per year. But the rate can change according to both precipitation levels and temperature, which affect how much limestone enters solution. It is part of the building evidence of a warming planet.  

Talking of the Victorians, one section of the cave is named Eldon Hall after John Scott (later Lord Eldon), who (in the 1830s) was a friend of the cave’s Victorian landowner, James Farrer of Ingleborough Hall. Lord Eldon was a late 18th Century pupil at RGS before eloping with Bessie Surtees and later becoming Lord Chancellor. Eldon House, right? Time and Lords: small world.