Wednesday, 26 August 2009

Jurassic Coast

Some pictures from a walk along part of the Jurassic Coast, between Sidmouth and Beer (yes, there's a place in Devon called Beer. Happy now?). It's geologically spectacular, as even I can see, and I've no great interest in geology, to be honest. It's an area where you can - will - find fossils as well; we found the odd fossil shell, and a few chunks of rocks that appeared to be made up almost entirely of fossilised gastropod molluscs. There's also the ammonite pavement further to the east, of which I've blogged some photos in the past.

If you're going out there to have a look at the cliffs, CHECK THE TIDE TIMES! There's nowhere to escape along many of the beach sections if you get it wrong. Tide tables are easy enough to find, although most of the local lifeboat callouts seem to be for people taking inflatables out onto the sea... Anyway, here goes with the tour.

Down at the eastern end of the site, the cliffs are well vegetated, with a wide beach below them. Older landslips and slumps have been stable for a long time, so there's a lush coastal vegetation on it. We found a number of species with somewhat interesting names here - Ploughman's Spikenard and Purple Gromwell to name just two!

As you head westwards, the beach slims down - the rock is harder and hasn't slumped, but is eroding gradually - you can see the lines of clays (I think!) in the sandstone, and there's a line of salmon-pink rock salt that runs along with them. In a couple of places, the rock salt appears to be the only thing holding some undercut sections onto the cliff; somewhat unnerving to wander along under those!

A closer view of some of those strata. Foolishly, I didn't take any closeups of the rock salt line. The seeps here are too steep to be colonised by much vegetation, but there are a few plants clinging grimly to their niches near the top. Tenacity embodied...

A little further westward, and you're back to softer rock - the slumping is old again... In fact, if you look carefully into the centre left of the picture, there's some tufa formations lurking on the cliffs.

Here's a closer look at the tufa. Limestone deposited from the seepage, this then colonised by the mosses you can see all over it. I know it's not the best picture, but it's reasonably interesting. If you like that kind of thing...

A little further on again, and a recent landslip. This was a real biggie. The cliff here slips and slumps on a regular basis - and this isn't even one of the biggest. One in May 2008 is described as 'the biggest in 100 years', taking a 400m stretch of cliff down. Mind you, the comment about 'destroying 400m of World Heritage coastline' is a bit excessive - the coastline's still there, after all... Interestingly, there was a cracking collection of arable 'weeds' at the base of this fall, including a nice bit of Sharp-leaved Fluellen; a new plant species for both of us.

Another look at the recent slip. Looking to the top of the cliff, there are two small points of rock sticking up there...
...and between them is still strung the fence along the now-vanished section of South West Coast Path. It's probably a good thing no-one was walking it at the time. Just goes to show that warnings about keeping well back from the edge might just - just - be worth heeding. Occasionally.

Beyond this point, the cliffs revert to a more solid stone again, with an increasingly narrow shingle beach at it's foot.

Most of the erosion on this particular section of cliff comes from water washing down it, I assume, so gullies form between outcrops of Black Bog-rush Schoenus nigricans. All nicely even along the base, where the salt influence is too great for the plants.

Towards the Sidmouth end, where the beach is very narrow - and the cliffs eroding to a more stable face - it all gets a tad precipitous. You get that uncanny feeling of something like vertigo as you look up sheer and bulging cliff faces. Awesome sight, though.

Looking to Sidmouth along the dramatic red cliff section. It's much more red in reality - honest.

If you're still awake, there's plenty more out there. Try Wikipedia for a start...

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