The Yorkshire Branch trip to Castleton was led by Tony Felski on a fine and dry day with only myself and 3 others attending. This made for an intimate and friendly group. We met by the bus stop at the Blue John Cavern at 10 and started by looking at Mam Tor.
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| View of the ridge |
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| Mam Tor |
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| Close up of turbidite sequences |
To the right, the main part of Mam Tor are the Mam Tor beds which are turbidite sequences, part of the Millstone Grit series. To the left are the Edale Shales which are older and lie directly on the limestone (below).
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| Edale Shale |
Building the road on top of the Edale Shales was probably the main reason that it slipped beyond repair. The landslip is still active today and we saw the front of the landslip later.
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| Old road |
From here we walked down the old road to Odin Gorge. Here a large lead vein was mined at the surface.
Near the Odin Mine crushing circle is the front of the landslip.
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| Front of landslip |
Around these area small pieces of Blue John, galena and baryte can still be found.
Walking from Castleton towards Winnats Pass we saw lava and beach beds.
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| Lava |
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| Beach beds in the Speedwell Mine carpark |
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| Front of reef |
On the way the sun was shining so I took this view up Winnats Pass earlier in the day.
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| What a view! |
We walked up the reef observing the change in dip. The beach beds (aka Apron Reef) had a dip of about 25 degrees while the forereef was 35 degrees. The slope evened out at the reef top and sloped backward in the back reef. Finally in the lagoon the beds are flat, although they are mostly covered in sediment now.
The final stop was at Windy Knoll where we saw algal deposits, bitumen and a neptunian dyke.
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| Algal deposits form the reef |
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| Now you see it, now you don't. A Neptunian Dyke. |
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| Another great view! |
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| Bitumen at the top of the knoll |
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