Arrangements of Seashells

Arrangement of Seashells 1 - Mostly small variegated scallop shells with a Manila Clam, top shells, and sea glass, in a bowl of water - common British seashells.

I really like to look at shells and have them around me. I often discover the odd shell in my pocket as a souvenir of a trip to the beach. Sometimes I will collect empty shells in larger numbers where this is permitted. The pictures in this post show different assortments and arrangements of common British seashells that have decorated my home from time to time over the last couple of years.

There are many posts on Jessica’s Nature Blog about seashells – sometimes just showing pretty pictures (like here) but often also describing their identifying features and other information. Click here if you would like to browse through more than 60 SEASHELL POSTS.

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Limpets on rusty iron

Limpets on rusty iron (1) -  Living limpet (Patella sp.) attached to rusty iron seaside pier.

I like the appearance of rust and I’m always looking out for interesting colours, patterns, and textures in oxidising iron. A good place to look is the metalwork on seaside groynes and piers which are invariably corroded by seawater. I find it amazing that small seaside creatures like limpets settle in these seemingly inhospitable locations where they eek out a living by grazing the microscopic algae that coat the surfaces. In their turn, as the limpets cling on to these man-made objects, the shells become stained by the orange of the rust and the green of the algae so that they blend into the overall constantly evolving design.

Limpets on rusty iron (2) -  Living limpet (Patella sp.) attached to highly coloured, patterned, and textured rusty iron seaside pier.

Limpets on rusty iron (3) -  Living limpet (Patella sp.) attached to highly coloured, patterned, and textured rusty iron seaside pier.

Limpets on rusty iron (4) -  Living limpets (Patella sp.) attached to highly coloured, patterned, and textured rusty iron seaside pier.

Limpets on rusty iron (5) -  Living limpet (Patella sp.) attached to highly coloured, patterned, and textured rusty iron seaside pier.

Limpets on rusty iron (6) - Living limpet (Patella sp.) attached to highly coloured, patterned, and textured rusty iron seaside pier.

Limpets on rusty iron (7) - Living limpet (Patella sp.) attached to highly coloured, patterned, and textured rusty iron seaside pier.

Limpets on rusty iron (8) - Living limpet (Patella sp.) attached to highly coloured, patterned, and textured rusty iron seaside pier.

Limpets on rusty iron (9) - Living limpet (Patella sp.) attached to highly coloured, patterned, and textured rusty iron seaside pier.

Limpets on rusty iron (10) - Living limpet (Patella sp.) attached to highly coloured, patterned, and textured rusty iron seaside pier.

Limpets on rusty iron (11) - Living limpet (Patella sp.) attached to highly coloured, patterned, and textured rusty iron seaside pier.

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Ancient Gower Shells & Raised Beaches

Ancient Gower Shells & Raised Beaches (1) - Limpet shells from 125,000 to 130,000 years ago, in raised beach deposits dating from the Ipswichian Interglacial Period, near Worms Head Causeway, Rhossili Bay, Gower, South Wales.

Britain began to warm up after the first stage of glaciation,  between 130,000 and 125,000 years ago, and rising seas caused by the melting of the ice sheets carved wave-cut platforms in coastal bedrocks, and deposited new beaches. In Britain this time is known as the Ipswichian Interglacial period – in geological terms a relatively recent phase of the Pleistocene xx. Subsequently, following various geological stages of ice formation and recession, sea levels dropped again to current day levels – leaving these earlier beaches up to 6 metres above present Chart Datum.

Remnants of these raised beaches have been described from around the coastline of the Gower Peninsula in South Wales. Most of the readily available academic texts refer to the sites at Foxhole, Langland, and at Fall Bay. Despite the focus on a few locations which demonstrate the phenomenon particularly well, there would have to be evidence of this sea level change all around the Gower Peninsula – and I discovered for myself an apparently hitherto un-described location for these ancient shell-bearing deposits right on the tip of the Rhossili Headland where it drops down to the Worms Head Causeway.

Here I found ancient limpet shells (Patella spp.) and winkle shells (Littorina spp.), embedded with minute shelly fragments and pebbles, in a matrix of reddish, iron-stained sediment consolidated by crystalline calcium carbonate. These deposits were located in cracks and crevices of the jagged limestone bed-rock projecting upwards at steep angles from the shore. More significantly, however, the shells were found in distinct, horizontally-aligned strata clearly visible at the base of the softer recent sediments leading down to the present-day beach.

The layers of ancient beach material originally would have spread out and covered all the bedrock which juts up from the upper and middle shore. It has now been mainly washed away but remains in a few places, almost like a coating of conglomerated cement with hard-core, attached to the Carboniferous limestone outcropping on the higher shore. The horizontal layers of raised beach deposits, seen in vertical section at the base of the headland, are often undercut by extreme high-tide wave action and consequently overhang slightly. Above the raised beach levels are solifluction deposits and red soil.

For more information about the raised beaches of Gower, have a look at:

George, G.T. (2008) The Geology of South Wales – A Field Guide, published by gareth@geoserve.co.uk, ISBN 978-0-9559371-0-1, pp 66-89.

Mullard, Jonathan (2006) Gower, Collins New Naturalist Series, Harper Collins Publishers, London, ISBN-13 978-0-00-716067-6, ISBN-10 0-00-716066-6, pp 44-50.

PS Don’t forget that you can click on individual photographs to enlarge them and read a detailed description of the image.

Ancient Gower Shells & Raised Beaches (2) - Limpet shells from 125,000 to 130,000 years ago, in raised beach deposits dating from the Ipswichian Interglacial Period, near Worms Head Causeway, Rhossili Bay, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (3) - Limpet (Patella spp.), winkle (Littorina spp.), and other shell fragments shells from 125,000 to 130,000 years ago, in iron-stained stalagmitic calcium carbonate matrix, in  raised beach deposits, near Worms Head Causeway, Rhossili Bay, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (4) - Winkle and limpet shells cemented in a hardened matrix with pebbles and shell fragments, in part of a raised beach, dating from the Ipswichian Interglacial 125,000 to 130,000 years ago in the Pleistocene - found between Carboniferous limestone layers at Worms Head Causeway, Rhossili, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (5) - Limpet shells from 125,000 to 130,000 years ago, in raised beach deposits dating from the Ipswichian Interglacial Period, near Worms Head Causeway, Rhossili Bay, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (6) - Limpet shells from 125,000 to 130,000 years ago, in raised beach deposits dating from the Ipswichian Interglacial Period, near Worms Head Causeway, Rhossili Bay, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (7) - Winkle shells (Littorina spp.) from 125,000 to 130,000 years ago, in raised beach deposits dating from the Ipswichian Interglacial Period, near Worms Head Causeway, Rhossili Bay, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (8) - Winkle shell (Littorina spp.) from 125,000 to 130,000 years ago, in raised beach deposits dating from the Ipswichian Interglacial Period, near Worms Head Causeway, Rhossili Bay, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (9) - Winkle shells (Littorina spp.) from 125,000 to 130,000 years ago, in raised beach deposits dating from the Ipswichian Interglacial Period, near Worms Head Causeway, Rhossili Bay, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (10) - Shell fragments from 125,000 to 130,000 years ago, embedded in an iron-stained calcite cement (seen here as a network of crystalline strands), in raised beach deposits dating from the Ipswichian Interglacial Period, near Worms Head Causeway, Rhossili Bay, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (11) - Shell fragments and gravel  from 125,000 to 130,000 years ago, embedded in an iron-stained calcite cement (seen here in close-up as a network of crystalline strands), in raised beach deposits dating from the Ipswichian Interglacial Period, near Worms Head Causeway, Rhossili Bay, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (12) - Shells and pebbles in a raised beach naturally cemented together by rusty-coloured calicite cement. Dating from the Ipswichian Interglacial Period 125,000 to 130,000 years ago. Photographed on the tip of the Rhossili Headland where it drops down to the Worms Head Causeway, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (13) - Over-hanging layers of ancient raised beach deposits with pebbles and marine shells, formed during an interglacial period 125,000 to 130,000 years ago, on the landward edge upper shore of the Worms Head Causeway, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (14) - Over-hanging layers of ancient raised beach deposits with pebbles and marine shells, formed during an interglacial period 125,000 to 130,000 years ago, seen on the landward (Rhossili) edge of the upper shore of the Worms Head Causeway, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (15) - Layer of ancient raised beach deposits with pebbles and marine shells, formed during an interglacial period 125,000 to 130,000 years ago, forming a carpeting layer cemented to wave-cut bed-rock, seen on the landward (Rhossili) edge of the upper shore of the Worms Head Causeway, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (16) - Layer of ancient raised beach deposits with pebbles and marine shells, formed during an interglacial period 125,000 to 130,000 years ago, forming a carpeting layer cemented to wave-cut bed-rock. A chunk of the deposit has become detached.  Vertical section of raised beach deposits, solifluction debris, and red soil derived from Old Red Devonian sandstone seen in background. Photographed on the landward (Rhossili) edge of the upper shore of the Worms Head Causeway, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (17) - Layer of ancient raised beach deposits with pebbles and marine shells, formed during an interglacial period 125,000 to 130,000 years ago, forming a carpeting layer cemented to wave-cut bed-rock. Another layer can be seen overlying it and extending seawards, while the vertical section of raised beach deposits, solifluction debris, and red soil derived from Old Red Devonian sandstone is visible  in background - with the lowest layer undercut and overhanging the beach. Photographed on the landward (Rhossili) edge of the upper shore of the Worms Head Causeway, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (18) - Over-lapping and protruding layers of ancient raised beach deposits with pebbles and marine shells, formed during an interglacial period 125,000 to 130,000 years ago, with solifluction debris, and red soil derived from Old Red Devonian sandstone also visible, with the lowest layer undercut by high tide wave action and overhanging Carboniferous Limestone bed-rock below. Photographed on the Rhossili Headland edge of the Worms Head Causeway, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (19) - Deep red soil (derived from Old Red Devonian rocks) obscuring the raised beach deposits at the base of the Rhossili Headland, adjacent to the Worms Head Causeway, Gower, South Wales.

Ancient Gower Shells & Raised Beaches (20) - The jagged rows of Carboniferous Limestone, jutting up from the upper shore of the Worms Head Causeway near the Rhossili Headland, would all at one time have been overlain by ancient raised beach deposits with pebbles and shells. These have been mostly eroded away by wave action. At the present time, remnants of these old beach layers still remain at the top of the shore.

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