Marros west - cryogenic anticline and solifluction deposits 2

Carmarthenshire

Among Earthwatcher's albums  >  Wales


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Cliff section east of Amroth 2

Telpyn Point to Amroth Between Amroth and Telpyn Point, magnificent cliff sections expose the upper Namurian sequence of deltaic channel-fill sandstones and intervening shale sequences. About 1.5 km east of Amroth, this photo shows the sequence gently dipping to the west. At the top of the cliff are brown sandstones: the lowest in the Coal Measures sequence. Below this are dark mudstones of the Gastrioceras subcrenatum Marine Band which marks the base of the Coal Measures. This is underlain by the Telpyn Point Sandstone (formerly designated as the Upper Sandstone), the uppermost main sandstone in the Namurian, and originally known as the 'Farewell Rock', so called because exploratory boreholes and shafts for coal penetrating the sandstone would no longer encounter any workable coals. Underlying the sandstone is a shale sequence. See notes for details.

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Cliff section east of Amroth 1

Telpyn Point to Amroth Between Amroth and Telpyn Point, magnificent cliff sections expose the upper Namurian sequence of deltaic channel-fill sandstones and intervening shale sequences. About 1.5 km east of Amroth, this photo shows the sequence gently dipping to the west. The dark mudstones of the Gastrioceras subcrenatum Marine Band which marks the base of the Coal Measures can be seen near the top of the cliff. This is underlain by the Telpyn Point Sandstone (formerly designated as the Upper Sandstone), the uppermost main sandstone in the Namurian, and originally known as the 'Farewell Rock', so called because exploratory boreholes and shafts for coal penetrating the sandstone would no longer encounter any workable coals. Underlying the sandstone is a shale sequence, with another sandstone (pale brown-grey) visible near the base of the cliff. See notes for details.

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West of Telpyn Point - fault in Telpyn Point Sandstone group

Telpyn Point to Amroth Between Amroth and Telpyn Point, magnificent cliff sections expose the upper Namurian sequence of deltaic channel-fill sandstones and intervening shale sequences. This photo shows a normal fault (in the centre) downthrowing approx.10 m to the east (right). The dark band just below the top of the cliff on the eastern side is a thin coaly horizon. Overlying this are mudstones of the Gastrioceras subcrenatum Marine Band which marks the base of the Coal Measures. The main part of the cliff section is in the Telpyn Point Sandstone (formerly designated as the Upper Sandstone), the uppermost main sandstone in the Namurian, and originally known as the 'Farewell Rock', so called because exploratory boreholes and shafts for coal penetrating the sandstone would no longer encounter any workable coals. Underlying the sandstone is a shale sequence. See notes for details.

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Marros west - cryogenic anticline and solifluction deposits 2

Marros Sands to Amroth Just east of Amroth, we cross the county boundary into Carmarthenshire. The fine beach of Marros Sands, some 4 km east of Amroth is relatively isolated between Telpyn Point and Ragwen Point. There is no road access; the only way to get here is along the coastal paths, along the beach at lowest tide, or by boat. At the western end of Marros Sands the Teague's Wood valley cuts down to the beach. The valley centre is filled with solifluction deposits ('Head') formed by freeze-thaw cycles of permafrost melting and refreezing at the end of the last glacial period (Devensian). This is a closer view of the cryogenic anticlinal fold in the shales of the Bishopton Mudstone Formation The fold is probably due to valley bulging during melting of the permafrost. The fold is quite superficial and probably does not extend more than a few metres into the sub-surface. Overlying the shales are angular, frost-shattered, shale fragments, possibly with some upward pointing ice-wedging structures. This is overlain in turn by a paler, angular, solifluction 'Head' and modern river alluvium, mostly sand with rounded pebbles and cobbles. See notes. The walking stick is approx. 90 cm long

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Marros west - cryogenic anticline and solifluction deposits 1

Marros Sands to Amroth Just east of Amroth, we cross the county boundary into Carmarthenshire. The fine beach of Marros Sands, some 4 km east of Amroth is relatively isolated between Telpyn Point and Ragwen Point. There is no road access; the only way to get here is along the coastal paths, along the beach at lowest tide, or by boat. At the western end of Marros Sands the Teague's Wood valley cuts down to the beach. The valley centre is filled with solifluction deposits ('Head') formed by freeze-thaw cycles of permafrost melting and refreezing at the end of the last glacial period (Devensian). In the centre is a cryogenic anticlinal fold in the shales of the Bishopton Mudstone Formation The fold is probably due to valley bulging during melting of the permafrost. The fold is quite superficial and probably does not extend more than a few metres into the sub-surface. Overlying the shales are angular, frost-shattered, shale fragments, possibly with some upward pointing ice-wedging structures. This is overlain in turn by a paler, angular, solifluction 'Head' and modern river alluvium, mostly sand with rounded pebbles and cobbles. See notes. The walking stick is approx. 90 cm long.

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Marros west - Teague's Wood and drift-filled valley

Marros Sands to Amroth Just east of Amroth, we cross the county boundary into Carmarthenshire. The fine beach of Marros Sands, some 4 km east of Amroth is relatively isolated between Telpyn Point and Ragwen Point. There is no road access; the only way to get here is along the coastal paths, along the beach at lowest tide, or by boat. At the western end of Marros Sands the Teague's Wood valley cuts down to the beach. The valley centre is filled with solifluction deposits ('Head') formed by freeze-thaw cycles of permafrost melting and refreezing at the end of the last glacial period (Devensian).

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Telpyn-Marros panorama

Marros Sands to Amroth Just east of Amroth, we cross the county boundary into Carmarthenshire. The fine beach of Marros Sands, some 4 km east of Amroth is relatively isolated between Telpyn Point and Ragwen Point. There is no road access; the only way to get here is along the coastal paths, along the beach at lowest tide, or by boat. In this panoramic view, the cliffs to the right of centre are immediately south of Top Castle hill fort and are comprised of shales of the Namurian-age Bishopston Mudstone Formation (Middle Shale Group). Erosion along joint planes has produced a series of scalloped caves and collapses, and remnant low stacks and reefs on the wave-cut platform. To the west (left) the Teague's Wood valley cuts down to the beach, with the headland of Telpyn Point beyond. Structurally, these rocks are almost completely undisturbed, compared with the thrusts and folds encountered just a few miles to the west, between Amroth and Tenby. Panorama constructed from six landscape format photos sticthed together using Photoshop software. Best viewed LARGE on a black background.

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Marros west cliffs

Marros Sands to Amroth Just east of Amroth, we cross the county boundary into Carmarthenshire. The fine beach of Marros Sands, some 4 km east of Amroth is relatively isolated between Telpyn Point and Ragwen Point. There is no road access; the only way to get here is along the coastal paths, along the beach at lowest tide, or by boat. The cliffs immediately south of Top Castle hill fort are comprised of shales of the Namurian-age Bishopston Mudstone Formation (Middle Shale Group). Erosion along joint planes has produced a series of scalloped caves and collapses, and remnant low stacks and reefs on the wave-cut platform. Structurally, these rocks are almost completely undisturbed, compared with the thrusts and folds encountered just a few miles to the west, between Amroth and Tenby.

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Marros Sands and Top Castle hill fort panorama

Marros Sands to Amroth Just east of Amroth, we cross the county boundary into Carmarthenshire. The fine beach of Marros Sands, some 4 km east of Amroth is relatively isolated between Telpyn Point and Ragwen Point. There is no road access; the only way to get here is along the coastal path, along the beach at lowest tide, or by boat. This is an easterly panoramic view from the coast path passing through Teague Wood. On the distant skyline, the higher ground east of the Gwendraeth valley is in the centre; the Gower peninsula to the right of centre. The prominent hill dominating the left view is Top Castle Iron-age hill fort, with its ramparts visible in the scrub vegetation. Panorama constructed from three landscape photos stitched together using Photoshop software. Best viewed LARGE on black background!
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