Eype Beach Stream 3

Little pebble bridges over a beach stream

On the western half of the shore at Eype in Dorset, England, the cliff is basically made up of porous yellow sandstones and limestones, belonging to the Middle Jurassic Down Cliff Sand Member and Thorncombe Sand Member, overlying the pale, blue-grey micaceous silty mudstone and shale known as the Eype Clay Member. All three members belong to the Dyrham Formation.  Rainwater soaks down through the upper porous rocks but, when it reaches the lower clay-based strata, it seeps out to the surface and drains away down the cliff face to the shore in numerous small streams.

The picture above, and the short video clip below, show one of these little streams running over the clay where someone has artistically constructed small pebble bridges over the flow. The last image in the post illustrates the general appearance of the cliff face with the small streams issuing from the lower layers.

Blue-grey clay and yellow sandstone strata at Eype Beach

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Lyme 8

 

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Lyme 7

 

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Rock Textures at Eype 1

View of the cliff on the western shore at Eype showing stratification

View of the cliff on the western shore at Eype showing stratification

The interesting thing about Eype Beach is that you don’t have to climb the cliffs to see the rocks in detail – the rocks come to you! Boulders of sandstone and limestone from high in the cliffs regularly collapse to the beach, which becomes strewn with them, and affords an opportunity to examine the composition of, and the fossil content of, the variety of rock types represented in the strata above shore level. Even the low, thick band of softer mudstones and shales slips down on a fairly regular basis, and liquified by small streams, oozes over the shingle of the upper beach.

It’s going to take me a while to work out which rock is which. However, I can say that Eype Beach has two different geologies more or less separated at Eypesmouth where a small stream cuts its way down a steep-sided valley through the predominantly soft rocks. If you turn right and westwards where the stream breaks through to the shore, and walk towards Thorncombe Beacon as I did, then on your right-hand side are cliffs made up of several virtually horizontal rock strata of different types of sedimentary rock. The lowermost layer, nearest to the level of the shingle beach, is a 55 foot depth of blue-grey Eype Clay Member made up from micaceous silty mudstone and shale – also called  the Micaceous Beds – from the Middle Jurassic Period.

Above the blue-grey mudstone, are the yellow layers of silts and sandstones of the Down Cliff Sand Member and the Thorncombe Sand Member – with sporadic fossil beds, and thinner bands of calcareous sandstone and ironshot limestone. You can easily see the contrasting colours of the different rocks in the cliff face.

I had hoped to find some brittle star fossils, that was the main aim of the visit, but I wasn’t lucky on this occasion. It was rather hot on the day and I don’t think I walked far enough along the shore to be in the most likely location. The Starfish Bed with Palaeosoma egertoni is at the very base of the Down Cliff Sand Member which itself overlies the Eype Clay Member. Large blocks of this rock fall to the beach – but you have to hope that the block has fallen the right way up for you to see the brittle star fossils, and also hope that a professional fossil hunter has not got there before you! I’ll have to keep on keep searching.

View looking west toward Thorncombe Beacon from the base of the cliff at Eype

View looking west toward Thorncombe Beacon from the base of the cliff at Eype

It was clear that many types of rock were identifiable on the beach; even the modern mud-slicks and clay seepages were interesting because they demonstrate and replicate the same  processes that would have contributed to the textures and patterns of the ancient rocks. As the soft muds dried out in the sun, the surfaces were beginning to form a crazy paving patchwork of cracks – the same as could be observed in nearby slabs of rock. As the liquified clays dribbled outward from the base of the cliff rock exposure, they incorporated assemblages of small pea-sized pebbles and who-knows-what man-made objects that might end up in rock strata of the future.

So the gallery of pictures today just shows details of a small selection of the rocks and sediments to be found on Eype Beach with a range of the natural textures and patterns they exhibit. It’s the starting point for the Eype geological learning journey.

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Eype Beach Stream 1

Lyme 4

Large Jurassic ammonite fossil in a beach boulder

An abundance of Jurassic ammonites – seen on a single walk along the shore at Monmouth Beach in Dorset, England, a few years back. There were large ones and small ones; embedded in beach boulders and forming rock pavements; in limestone and shale; some crystallised and others just impressions; some with other fossils preserved alongside or even inside the chambers.

Large Jurassic ammonite fossils embedded in a rock platform on the beach

Small ammonite fossil in Jurassic limestone

Impression of a small ammonite fossil

Large Jurassic ammonite fossil in a beach boulder

Large Jurassic ammonite fossils embedded in a rock platform on the beach

Large Jurassic ammonite fossils embedded in a rock platform on the beach

Large Jurassic ammonite fossil in a beach boulder

Ammonite fossil on Monmouth Beach at Lyme Regis

Ammonite fossil on Monmouth Beach at Lyme Regis

Large Jurassic ammonite fossil in a beach boulder

Large Jurassic ammonite fossil in a beach boulder

Monmouth Beach at low tide

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Ringstead Sea Kale

Young curly leaf of Sea Kale just opening

Close-up of a young red and purple leaf of Sea Kale

Sea Kale, Crambe maritima Linnaeus, grows on the shingle beaches in Dorset, England. When the leaves first sprout, they are a delectable colour of purple but as the plant matures the leaves become grey-green. However, the leaf veins and the curly edges of the leaves remain pink/purple but not as intense a colour as in the young shoots.

Sea Kale leaf becoming greener as it develops but with purple veins and edges

Close-up of a semi-mature Sea Kale leaf with leaf veins and curly edges still coloured purple or deep pink

Close-up of well developed Sea Kale leaf showing pink/purple leaf edges

Close-up of well developed Sea Kale leaf with grey-green blade and just the edges pink

Sea Kale (Crambe maritima) growing on the beach

A Sea Kale plant growing on seashore shingle at Ringstead Bay

Sea Kale (Crambe maritima) growing on the beach

Sea Kale (Crambe maritima) growing on the beach

Young purple shoots at the base of Sea Kale (Crambe maritima) growing on the beach

Young purple shoots sprouting at the base of Sea Kale (Crambe maritima) growing on the Ringstead Beach

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