Rainbow rocks & beach graffiti (2)

Here are some more photographs of graffiti on the rainbow-coloured sandstone cliffs and beach boulders at Studland, Dorset. It seems like something inherent in human nature compels so many people to leave a souvenir of their visit inscribed in stone.

I do not think that anything could be done to stop people carving the rocks. I do not think there would be any point in trying to clean the rocks up. The natural flaking and peeling, weathering, and sea erosion of the stone surfaces tends to soften the affect of the carvings. 

Actually, the carvings are so ubiquitous in this location that they seem part of the natural landscape – to the extent that most people probably do not even notice them. They do not detract from the beauty of the place.

There are some earlier posts with more pictures of the rocks and rock carvings at this place. Click here for Rainbow rocks & beach graffiti , Studland rocks in autumn, and Rock carvings at Studland in February.

 

© Jessica Winder and Jessica’s Nature Blog, 2009. Unauthorised use and/or duplication of this material, including both text and photographs, without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jessica Winder and Jessica’s Nature Blog with appropriate and specific direction to the original content.

 Photographs in this blog are copyright property of Jessica Winder with all rights reserved

Natural pattern of seaweed on rock (4)

 

Natural arrangement of red seaweed washed onto the rocky platform at Lyme Regis, Dorset, UK – part of the Jurassic Coast.

© Jessica Winder and Jessica’s Nature Blog, 2009. Unauthorised use and/or duplication of this material, including both text and photographs, without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jessica Winder and Jessica’s Nature Blog with appropriate and specific direction to the original content.

 Photographs in this blog are copyright property of Jessica Winder with all rights reserved

Pebbles with holes made by tube worms

Continuing the theme of pebbles with holes made by sea creatures, the photographs here show pebbles of soft sedimentary rock which bear, not only the larger sort of hole made by boring bivalved molluscs, but also many much smaller holes.

These small holes may be seen in some instances to occur in pairs that represent both openings of the U-shaped tunnel that has been dissolved into the stone by the presence of a mudtube-dwelling marine bristle worm or (polychaete) such as the ubiquitous Polydora ciliata (Johnston).

The tunnels in the rock can often be seen like narrow open channels on the surface. This happens in the pebbles that are old and in which the outer layer has been eroded away by mechanical damage.

Earlier posts on the burrowing damage caused by small marine mudtube-dwelling polychaetes can be found in Flat oyster shells with Polydora ciliata burrows and Ancient & modern Polydora ciliata type burrows in Flat Oyster shells.

 

© Jessica Winder and Jessica’s Nature Blog, 2009. Unauthorised use and/or duplication of this material, including both text and photographs, without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jessica Winder and Jessica’s Nature Blog with appropriate and specific direction to the original content.

 Photographs in this blog are copyright property of Jessica Winder with all rights reserved

Beach Art 5 – Zen Rubbish

Beauty in everything/anything? A large lump of melted plastic rubbish has been converted into an object for peace and contemplation. Elegantly placed on a bed of raked sand, bordered by small stones and pebbles, the unknown artist has designed a Zen Garden on the seashore.

© Jessica Winder and Jessica’s Nature Blog, 2009. Unauthorised use and/or duplication of this material, including both text and photographs, without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jessica Winder and Jessica’s Nature Blog with appropriate and specific direction to the original content.

 Photographs in this blog are copyright property of Jessica Winder with all rights reserved

Frost-damaged rocks at Whiteford?

In the previous post I mentioned the glacial till exposure near Whiteford Point, Gower. According to expert accounts, some of these rocks show frost damage caused by the ice sheet and the icy conditions 17,000 years ago. The photographs in this post illustrate what I believe to be some of these frost-damaged rocks. The stones in the first two pictures, exhibit multiple parallel splitting. The third image shows a stone, maybe of a different type, with a single crack. It is easy to imagine how the smaller pieces of stone that cleave from these rocks end up as the large, flat,  smoothed pebbles so typical of the beach further along to the north east. The final picture shows some of these pebbles with my walking pole to give scale.

The earlier related post is Pebbles, spits & banks at Whiteford (2).

 

 

 

 © Jessica Winder and Jessica’s Nature Blog, 2009. Unauthorised use and/or duplication of this material, including both text and photographs, without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jessica Winder and Jessica’s Nature Blog with appropriate and specific direction to the original content.

 Photographs in this blog are copyright property of Jessica Winder with all rights reserved

Pebbles, spits & banks at Whiteford (2)

At the remotest end of the Whiteford National Nature Reserve is a tranquil place where wild ponies and sheep graze. Here, you can find clues to the geological past of the area and observe evidence of current geological processes that will change and shape its future appearance.

Beneath the 3 Km length of the dune-covered Whiteford Burrows, lies a spit of  glacial till deposited by the ice sheet that once occupied the Loughor valley in the late Devensian period of 17000 years ago. These boulders, cobbles, and gravels were scooped up by the scouring action of the thick and heavy layer of ice as it extended downwards and outwards towards the sea. They can be seen outcropping between Whiteford Point and the old derelict Whiteford Lighthouse.

Despite subsequent sea level rises and falls, the deposit remains more or less intact. In some rocks there is evidence of ancient frost damage * from the ice sheet. Such damage facilitates the eventual break up of the rock into smaller, often flat, pieces. Once loosened, these smaller pieces are rolled around by the tides – thus acquiring rounded edges.

These pebbles have washed out from the original galacial deposit to form the base of a further spit that extends eastwards from the Point. Most of the time the pebbles here are covered by sand but they are sometimes visible as a band of stones at the top of the tidal reach especially when stormy waves have licked the sand away.

The pebbles within these exposures (of  the spit’s foundation) frequently appear to be layered or orientated in curving lines – reflecting the direction of the currents that carried them into position. In one particular place there is an additional recurved spit of pebbles, never covered by sand, pointing inland rather than offshore.  This is near to a branch of the Burry Pill stream that drains Landimore saltmarsh.

I am not certain what accounts for this structure because it looks as if  some sustained power would have been needed to create it. The sea does regularly cover the marshes but mostly creeps slowly up as the incoming tide combines with the outgoing estuary waters to raise the water level. I wonder whether the recurved pebble spit forms in extreme storm conditions when the sea takes a short cut across the main sand-covered spit. There is certainly a lower area of damper ground that could provide such a route.

* See the following post for more about frost-damaged rocks at Whiteford.

If you would like to read in some more detail about the geology of  this area, I would recommend two publications:

Classic Land Forms of the Gower Coast by E. M. Bridges (1997) published by the British Geomorphological Research Group and The Geographical Association. ISBN 1 899085 50 5

Carmarthen Bay by V. J. May (2007) Vol. 28: Coastal Geomorphology of Great Britain. Chapter 11: Coastal assemblage GCR sites. Site: CARMARTHEN BAY (GCR ID: 2102). Extracted from the Geological Conservation Review. 

 

© Jessica Winder and Jessica’s Nature Blog, 2009. Unauthorised use and/or duplication of this material, including both text and photographs, without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jessica Winder and Jessica’s Nature Blog with appropriate and specific direction to the original content.

 Photographs in this blog are copyright property of Jessica Winder with all rights reserved

Six abstract patterns with Lichen

Lichens are a strange kind of organism that is partly algae and partly fungi. They exhibit a great deal of variability in shape and colour and are found in all sorts of places – from the splash-zone rocks of the seashore, to high altitude boulders, to living and dead trees and wood, and man-made objects of almost every conveivable material – provided the environment is right. They are supposed to favour clean, fresh air. Each species has a defined habitat preference.

Lichens can be smooth and glossy coatings; dry and scabby encrustations; leaf-like; finely-branched; or lacey. They can grow as individuals that slowly increase in area and/or height. They can grow in groups of the same species that remain separate or that eventually coalesce to form a patchwork of similar colours – perhaps with matching or contrasting dots of colour provided by the fruiting bodies. They can grow intermingled with a variety of other lichen types with different, contrasting, or co-ordinating colours and morphology.

Though difficult to name, they are frequently interesting to observe. The abstract patterns that they make on variable substrates are often attractive and also a source of artistic inspiration.

 

© Jessica Winder and Jessica’s Nature Blog, 2009. Unauthorised use and/or duplication of this material, including both text and photographs, without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jessica Winder and Jessica’s Nature Blog with appropriate and specific direction to the original content.

 Photographs in this blog are copyright property of Jessica Winder with all rights reserved

Shells with holes made by boring bivalves

In an earlier posting I talked about pebbles with holes made by sea creatures and focussed primarily on the large burrows made by boring bivalved molluscs, like piddocks, in rocks. However,  evidence of rock-boring bivalves is also found in some very thick seashells which, to the infesting organisms, seem much the same as a soft stone. In the UK, the only native species of mollusc with shells that can potentially grow very thick like this is the European Flat Oyster (Ostrea edulis L.).

The photographs show the damage caused by boring bivalves in thick, old oyster shells from Gower beaches. It is not possible to tell definitely in each instance whether the oysters were infested while still alive, or whether the empty shell has been used after death. Damage like this has been recorded in ancient Roman oyster shells, for example, from archaeological excavations in Dorchester in Dorset. This is an indication that living oysters can be infested in this way since the shells here were food remains. The most likely species responsible for this infestation damage is the Flask Shell, Gatrochaena dubia (Pennant) – this likes to bore into organic carbonates as well as sandstone and limestone..

In some of the shells illustrated the burrows totally penetrate the shell. If this had happened while the shell was still occupied, then the animal would have been affected: it would have tried to lay down new layers of the type of shell that lines the internal cavity in order to protect itself – or it would have perished.

What would the Flask Shells be doing in the oyster shell? Basically, they would be using the shell (or rock) as a secure shelter. There is no deliberate aim to kill or damage the organism within. Flask Shells and other rock-borers enter a shell or rock crevice when they are small. The hole, burrow or tunnel is enlarged to accommodate them as they grow bigger. In fact, it may never be possible for the bivalve to leave the burrow because the entrance is much smaller than the animal. Empty shells are frequently found within the burrows. When this happens, it is possible to make a firm identification of the organism. When shells are absent from the burrow, a certain amount of educated guesswork (based on habitat preferences and geographical distribution) is required to suggest an identification.

How do rock-boring Flask Shells, Piddocks and other species create the burrows? These bivalves all have specially adapted shells, sometimes very tough and sometimes fragile depending on the hardness of the substrate they prefer to burrow into. There are often sharp ridges or spines on the outer surface of the shells. These bivalves scrape away the rock or shell they occupy in an ingenious way. They all have two exceptionally long and powerful fleshy siphons (tubes) for sucking water and food particles inwards and for expelling water and waste outwards. The siphons are often so large that they cannot be retracted into the cavity enclosed by the two hinged shells. They lie along the tunnel and connect the animal to the outer watery world. The animals use hydrostatic pressure via these siphons to force their shells outwards and grind away the stone or shell in which they burrow.  

The large diameter burrows, often about a centimetre across, provide windows to observe the internal structure of the shells. You can see that the shell is made up of a sequence of layers. These layers alternate between a narrow, more resilient shell type and a thicker, softer shell form. This reflects the complex microscopic make up of the shell where different types of shell occupy different positions in the morphology, and serve various functions. Peering closely into one of these rock-borer tunnels reveals a fascinating landscape resembling the strata of the Grand Canyon.

 

© Jessica Winder and Jessica’s Nature Blog, 2009. Unauthorised use and/or duplication of this material, including both text and photographs, without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jessica Winder and Jessica’s Nature Blog with appropriate and specific direction to the original content.

 Photographs in this blog are copyright property of Jessica Winder with all rights reserved

Rainbow rocks & beach graffiti

There’s something deep within the human psyche that drives people to leave their mark. Not so often to celebrate awe of nature, existence and survival, or contribute to ritual, as in the ancient cave paintings and carvings. More likely these days to simply say ‘I was here’; sometimes to make a declaration of affection; sometimes to express a creative urge.

It is clear that generation after generation of visitors to this particular site have recorded their presence by carving initials on the wonderful rainbow coloured sandstone of the cliffs and beach boulders. The engravings are layered one upon another in the stone. Natural processes of weathering and wear on the surface of the rock tend to smooth away or remove the older carvings over time – a kind of natural exfoliation or auto-cleaning – but there will probably always be new scratchings of graffiti to replace the old.

The natural colourings in the hardened iron-bearing sediments provide a fantastic multi-coloured canvass for the artists to work on. Some people have incorporated embedded geological features into their carvings. Despite the fact that the inscriptions are a ‘defacement’ of the rock strata, en masse they seem to have resulted in something of artistic merit – although I do not expect everyone to agree with that point of view.

 

© Jessica Winder and Jessica’s Nature Blog, 2009. Unauthorised use and/or duplication of this material, including both text and photographs, without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jessica Winder and Jessica’s Nature Blog with appropriate and specific direction to the original content.

 Photographs in this blog are copyright property of Jessica Winder with all rights reserved

Beached Shoes on Gower (2)

 

This is the second in the series of images of lost and abandoned footwear: shoes, boots, slippers, trainers and flip-flops found on the strandlines of Gower beaches. Some, like the wellington boots, have probably been lost overboard from pleasure or work boats; or from the back of the trailers and tractors that ferry cockle and mussel fishermen from shore to shore. Others might have been lost in the dark after late night beach parties; or washed away when the tide came in more quickly than expected while swimmers were in the water. I find it fascinating when shoes have obviously been in the sea a long time and have hydroids or barnacles attached. Other shoes I rediscover on different occasions and in different places; each time a little more worse for wear. Maybe one of these shoes belongs to you? Have a look and see.

If your lost shoe isn’t here, look in later posts on the same subject as I have many more examples in my collection still to show. 

Click here for the earlier posts about beached shoes from Gower and from Chesil Beach.   

 

 © Jessica Winder and Jessica’s Nature Blog, 2009. Unauthorised use and/or duplication of this material, including both text and photographs, without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Jessica Winder and Jessica’s Nature Blog with appropriate and specific direction to the original content.

 Photographs in this blog are copyright property of Jessica Winder with all rights reserved