The annual GeoWeek initiative was created by the British Geological Survey to promote “’active geoscience’ via a week of field trip activities taking place across the UK and Northern Ireland”. I’m a geologist, I’d just launched my own guided walking business (WildWays – please check it out) so this was right up my street…..

When: Friday 3rd May 2019

Meeting: Castleton Visitor Center Car Park, in the heart of the Peak District National Park

Route: Cave dale (limestone reefs), Windy Knoll, (biodegraded oil), Mam Tor (landslide and turbidites and shales), Odin’s mine (blue john, crinoids and other shells).


Four lovely clients met me in a very damp and wet car park in Castleton. Luckily the cafe was just opening, so taking advantage of the warmth and a hot cuppa, we discussed the days aims and big-scale geology undercover.

Donning our full waterproofs, we headed through the village, passed the limestone built houses and through a narrowed entrance up into Cave Dale. It’s a magical landscape in this small gorge, I always love it. It opens out at the top into rough grazing and fields.

Across the track, we were met by a farmer and his dogs moving the cows into one field and the ewes with lambs along the track (which we were headed) into another. It was perfect timing as we were allowed to walk through the track with the young lambs on their way to new pastures. Even the cows were friendly in the next field across.

“At the very top of the outcrop, the rock is dark, almost black. This is where the oil is!”

Windy Knoll

We descended to the rocky outcrop at Windy Knoll. Here, you can find the mineral galena – a silver, cubic-like shape shining amongst the dull grey of the limestone. At the very top of the outcrop, the rock is dark, almost black. This is where the oil is! It’s actually called biodegraded oil and has no use for anything as the microbial organisms that are found within the oil metabolize the petroleum (i.e. slowly eat it). If you put your nose close enough to the dark, muddy patches at the top of the outcrop, you can smell the hydrocarbons (or like your grandad’s garage).

Mam Tor

The rain hadn’t ceased and some of the group were getting cold. We decided to carry on and have a late lunch rather than stop and get colder; so onwards to the old road that runs at the base of Mam Tor. From here, you get a splendid view of the landslide. Also, what I love about this location is that you can make symmetries with the layering of the geology exposed by the landslide and the layering of the tarmac on the road.

Oden’s Mine

On to Odin’s Mine which gave some rest bite from the weather. On first inspection is what just a limestone cave, but looking more closely, more and more features could be seen in the rock – full crinoid (sea lilies) other shelly fossils, veins of blue john as well as modern living creatures such as cave dwelling spiders and their nests!

A leisurely walk took us back into Castleton. I hope everyone got something out of the day. There were plenty of questions and lots of interesting conversations.

If you fancy a geology themed walk, then please get in touch and I can create a memorable day out that will suit all abilities and interests.