Composition of Black Sediments at Rhossili

Composition of black beach sediments viewed under the microscope

Natural patterns on a sandy beachImages of patterns on the beach caused by wave action winnowing out lighter black sediments from the heavier yellow sand grains have been shown in earlier posts. Here are three microphotographs of the black sediments from a small sample that I scooped up on the shore at the time. Sorry there is no scale because I haven’t fathomed out how to include one in the images yet.

Natural patterns in black detritus on the strandline at Rhossili beachHopefully these shots are clear enough to show that the numerous black particles are small fragments of waterlogged wood; shiny hard pieces of coal (coal dust); a few large pale seeds not yet identified; minute fragmented seashells such as mussels; and many white slender organic objects which I think are small fish rib bones but could be or include heart urchin spines. It was these bones that gave the dried sample in the petri dish an almost fibrous appearance. I am going to see if I can find someone from the world of archaeology who would be familiar with the analysis of this type of material – to see if I can get some more specific information about these black sediments from the beach at Rhossili in Gower.

Composition of black beach sediments viewed under the microscope

Composition of black beach sediments viewed under the microscope

St Ann’s Provincial Park

St Ann’s Provincial Park along the Cabot Trail in Cape Breton Island, Nova Scotia, Canada, was just springing into life after a cold winter when we visited earlier this year. It was a brief stop for a picnic lunch on our way from the Cape Breton Highlands National Park to the Louisbourg area on the east coast. The park  lies on the northern shore of the stretch of water known as North Gut, and has a short trail leading to a look-off where there are views over the saltmarsh and St Ann’s Bay. We did not have time to venture very far down the trail but, even by the car park, there was plenty to enjoy.

Bright green ferns of various types were uncurling their fronds. The compacted fern buds are called fiddleheads. Particular varieties in some localities are a feature on menus at this time of the year (we tried some and they were delicious). Golden mosses covered the ground, while bladed marsh plants were breaking through the winter’s debris on the water margin. Delicate white blossoms quivered on trees of the woodland edge. The greatest delight was catching sight of a snake making its way through the leaf litter. I am not certain what sort but it might possibly be a Maritime Garter Snake.

Changes with the seasons – The Stile

Rural view with stile in summer on the Cerne Valley Trail, Dorset, England.

I’ve been recording the changes that come with season and weather as I walk along the Cerne Valley Trail in Dorset, England. The horse chestnut tree by the stile in these photographs is a convenient marker to illustrate the transition from bare branches of winter to full foliage in summer. Already, by September, the leaves are turning brown getting ready to fall. It is not only the tree that shows the changes but the ground cover vegetation, and the crops in the fields.

Natural Patterns at Cairns Botanic Gardens

It is cold today. I wanted to think of a time and place where it was much warmer. I thought back to the holiday I spent in Queensland, Australia, several years ago. It is a wet tropical region and the vegetation is luxurious in the Daintree Rainforest. We did explore the wild as best we could but there was nothing to beat visits to Cairns Botanic Gardens where we could enjoy the wonderful plants without so many of the attendant dangers. Here is a gallery of some of the amazing and beautiful natural plant patterns, colours and textures that I photographed among the vegetation in these fabulous gardens.

The stony west bank of Pennard Pill

Sea Lavender on lichen covered stones of the river bank at Three Cliffs Bay Just before the Pennard Pill watercourse takes a dramatic swing to loop around the giant sand dune to get to the shore at Threecliff (Three Cliffs) Bay on the Gower Peninsula, the right hand or west bank is composed of rough stones and then transitions into a salt marsh. [The area lies on the opposite side of the river to a more substantial and higher shingle bank that can be reached via a set of concrete stepping stones].

The low shingle surface of the right bank is relatively stable. Despite regular tidal inundations of brackish water, life clings to the limestone. Last August it was particularly attractive, covered with bright patches of yellow and black lichens, and ground-hugging clumps of partially red-stemmed plants with clusters of small pink flowers. I will have to find out what these plants are the next time I visit. I didn’t take close-ups. I had thought they might be Sea Heath (Frankenia laevis) but apparently that does not grow in this area – although it likes the same kind of habitat.  I think Sea Sandwort was also present. However, the numerous flowering stems of Sea Lavender I did recognise; and these plants were found equally spread in stony ground and on the wetter salt marsh area.

Tracks and Trails on Whiteford Sands

Furrowed trails made by common winkles on wet beach sand

You don’t exactly have to keep your nose to the ground to see them but you do have to be a keen observer to notice all the different tracks and trails left on the soft wet sediments of the beach at low tide. Larger marks left by people and vehicles are the first ones you see. Bird footprints are every where. The birds are feeding on all sorts of invertebrate seashore creatures like worms, small crustacea and molluscs – all of which leave holes, burrows and furrows as they move in and out of the sand and across the surface. Some of the pictures shown here simply aim to give the general context for the area of Whiteford Sands that I was walking across. If you look closely the other images, you will see not only the ripples in the sand but also the intricate network of traces left by the virtually invisible organisms that inhabit this ecosystem. The larger furrows in photos 1, 12 and 13 are made by the common winkle (Littorina littorea Linnaeus). I cannot name each animal that is responsible for each of the other types of trace. However, I am sure that there will be some specialists out there who could, especially those researchers concerned with the interpretation of trace fossils (the ichnologists).

Click images to view full size.

View looking west towards the sea at Whiteford Sands

View looking north-east towards the dunes at Whiteford Point

Wet seashore sand with marine invertebrate and other tracks and traces

Wet seashore sand with marine invertebrate tracks and traces with bird footprints

View looking north-east over wet seashore sand ripples with marine invertebrate tracks and traces at Whiteford Sands

Wet seashore sand ripples with marine invertebrate tracks and traces

Wet seashore sand ripples with marine invertebrate tracks and traces

Wet seashore sand ripples with marine invertebrate tracks and traces

Wet seashore sand ripples with marine invertebrate tracks and traces

Wet seashore sand ripples with marine invertebrate tracks and traces

Furrowed trails made by common winkles on wet beach sand

Furrowed trails made by common winkles on wet beach sand

The Rise and Fall of Whiteford Sands

View looking towards the lighthouse at Whiteford on the Gower Peninsula showing rock strewn beach with patches of sand

The photographs in this post illustrate the way that vast quantities of wind- and wave-borne sand at Whiteford Sands on the Gower Peninsula move around the shore over time. I have taken one fixed object, a piece of ancient timber with an unmistakable shape that projects from the early to post Holocene deposits of peat and clay, and taken shots of it on every visit to the beach over the past ten years or so. The following images show how the sand level changes periodically to reveal or conceal the underlying layers with the surface scattering of rocks that were dumped by the melting ice during the last glacial event. Beaches like Whiteford are incredibly dynamic. Click on any image in the gallery below to view as a slideshow in chronological order.

 

Autumn Horse Chestnut Leaf Miners

Natural patterns caused by moth caterpillar infestation in leaves

These remarkable patterns on leaves of the Horse Chestnut tree (Aesculus hippocastanum) result from a combination of the natural changing of the leaf colour in autumn and the effects of infestation by tiny caterpillars of the Horse Chestnut Leaf Miner moth (Cameraria ohridella). This Spanish species has invaded Britain in recent years and is having a very noticeable impact on the appearance of this one type of tree but it does not seem to have an effect on the wood of the tree. I have noticed a decline in the numbers of conkers this year, which might have had something to do with the loss of photosynthetic capability in trees that have been bady affected, but could be attributed to a number of other causes as well.

The tiny caterpillars live in the shallow space between the upper and lower layers of the leaf, and eat away systematically between parallel veins, killing that area of the leaf and leaving narrow bands of dead tissue that cover the leaf in irregular stripes. These can be seen increasingly throughout the summer in infected leaves but in autumn, as the leaves change colour and naturally die back for the winter, the damage caused by the caterpillars becomes more pronounced. It looks almost as if some artist has been having fun decorating the foliage to celebrate Halloween.