Pembrokeshire geology

Nolton Haven to Newgale The small Nolton-Newgale coalfield is separated by faulting from the main Pembrokeshire coalfield. It lies mostly within Pennant Sandstone Formation of the Upper Coal Measures rocks. The cliffs of Nolton Haven expose predominantly deltaic channel sandstones, often with highly erosive bases with coarse, rip-up, channel-lag deposits. The general dip is around 20° to the south-west. This photo shows planar laminated sandstones with an erosive base (marked by the walking stick handle) cutting into the underlying sandstone unit. Planar laminated sandstones in this setting often indicate high energy, fast current flow. The walking stick is 90 cm long.

Nolton Haven to Newgale The small Nolton-Newgale coalfield is separated by faulting from the main Pembrokeshire coalfield. It lies mostly within Pennant Sandstone Formation of the Upper Coal Measures rocks. The cliffs of Nolton Haven expose predominantly deltaic channel sandstones, often with highly erosive bases with coarse, rip-up, channel-lag deposits. The general dip is around 20° to the south-west. This photo shows planar laminated sandstones with an erosive base (marked by the walking stick handle) cutting into the underlying sandstone unit. The walking stick is 90 cm long.

Nolton Haven to Newgale The small Nolton-Newgale coalfield is separated by faulting from the main Pembrokeshire coalfield. It lies mostly within Pennant Sandstone Formation of the Upper Coal Measures rocks. The cliffs of Nolton Haven expose predominantly deltaic channel sandstones, often with highly erosive bases with coarse, rip-up, channel-lag deposits. The general dip is around 20° to the south-west. This photo shows laminated sandstones with two scoured channel bases cutting into the underlying channel-lag deposits. The walking stick is 90 cm long.

Nolton Haven to Newgale The small Nolton-Newgale coalfield is separated by faulting from the main Pembrokeshire coalfield. It lies mostly within Pennant Sandstone Formation of the Upper Coal Measures rocks. The cliffs of Nolton Haven expose predominantly deltaic channel sandstones, often with highly erosive bases with coarse, rip-up, channel-lag deposits. The general dip is around 20° to the south-west. This photo shows a close-up view the erosive channel-lag deposits with a prominent layer (approx. 30 cm thick) of ironstone pebbles.

Nolton Haven to Newgale The small Nolton-Newgale coalfield is separated by faulting from the main Pembrokeshire coalfield. It lies mostly within Pennant Sandstone Formation of the Upper Coal Measures rocks. The cliffs of Nolton Haven expose predominantly deltaic channel sandstones, often with highly erosive bases with coarse, rip-up, channel-lag deposits. The general dip is around 20° to the south-west. This photo shows a close-up view the erosive channel-lag deposits with a prominent layer of ironstone pebbles. The lens cap is 72 mm in diameter.

Nolton Haven to Newgale The small Nolton-Newgale coalfield is separated by faulting from the main Pembrokeshire coalfield. It lies mostly within Pennant Sandstone Formation of the Upper Coal Measures rocks. The cliffs of Nolton Haven expose predominantly deltaic channel sandstones, often with highly erosive bases with coarse, rip-up, channel-lag deposits. The general dip is around 20° to the south-west. This photo shows the erosive channel-lag deposits with a prominent layer of ironstone pebbles. The lens cap is 72 mm in diameter.

Nolton Haven to Newgale The small Nolton-Newgale coalfield is separated by faulting from the main Pembrokeshire coalfield. It lies mostly within Pennant Sandstone Formation of the Upper Coal Measures rocks. The cliffs of Nolton Haven expose predominantly deltaic channel sandstones, often with highly erosive bases with coarse, rip-up, channel-lag deposits. The general dip is around 20° to the south-west. This photo shows a close-up view of the erosive channel-lag deposits of sandstone blocks, ironstone pebbles and detatched coal lenses. The lens cap is 72 mm in diameter.

Nolton Haven to Newgale The small Nolton-Newgale coalfield is separated by faulting from the main Pembrokeshire coalfield. It lies mostly within Pennant Sandstone Formation of the Upper Coal Measures rocks. The cliffs of Nolton Haven expose predominantly deltaic channel sandstones, often with highly erosive bases with coarse, rip-up, channel-lag deposits. The general dip is around 20° to the south-west. This photo shows erosive channel-lag deposits of sandstone blocks, ironstone pebbles and detatched coal lenses all cutting down at a steep angle into the underlying sediments. The walking stick is 90 cm long.

Nolton Haven to Newgale The small Nolton-Newgale coalfield is separated by faulting from the main Pembrokeshire coalfield. It lies mostly within Pennant Sandstone Formation of the Upper Coal Measures rocks. The cliffs of Nolton Haven expose predominantly deltaic channel sandstones, often with highly erosive bases with coarse, rip-up, channel-lag deposits. The general dip is around 20° to the south-west. This photo shows erosive channel-lag deposits of sandstone blocks, ironstone pebbles and detatched coal lenses all cutting down at a steep angle into the underlying sediments. The walking stick is 90cm long.

Nolton Haven to Newgale The small Nolton-Newgale coalfield is separated by faulting from the main Pembrokeshire coalfield. It lies mostly within Pennant Sandstone Formation of the Upper Coal Measures rocks. The cliffs of Nolton Haven expose predominantly deltaic channel sandstones, often with highly erosive bases with coarse, rip-up, channel-lag deposits. The general dip is around 20° to the south-west.

A simplified interpretation of the previous photo of thrusted and faulted chevron folds in Namurian age siltstones and shales at Tenby North Sands. A panorama constructed from two landscape format photos stiched together in Photoshop. The vegetation does somewhat obscure the structure. Late winter would be a better time to view this exposure. Yellow - bedding plane traces. Red - thrusts and shear planes. The original photo is here: www.ipernity.com/doc/earthwatcher/48414314

Thrusted and faulted chevron folds in Namurian age siltstones and shales at Tenby North Sands. A panorama constructed from two landscape format photos stiched together in Photoshop. The vegetation does somewhat obscure the structure. Late winter would be a better time to view this exposure. A simplified interpretation of the structure is shown in the next photo here: www.ipernity.com/doc/earthwatcher/49952282

Thrusted and faulted chevron folds in Namurian age siltstones and shales at Tenby North Sands. The vegetation does somewhat obscure the structure. Late winter would be a better time to view this exposure. A panoramic view of this structure is here: www.ipernity.com/doc/earthwatcher/48414314 and a simplified interpretation is here: www.ipernity.com/doc/earthwatcher/49952282

Pembrokeshire Coast Path from St Govans to the Green Bridge of Wales The classic view of the Green Bridge of Wales sea arch, formed in the upper part of the Dinantian age Carboniferous Limestone Series. The small isolated sea stack to the right is probably the remnant pillar of a former sea arch, now collapsed, which joined on to the main arch pillar. The flat landform topography represents the '200 foot platform' - a Tertiary age marine erosion surface.

Pembrokeshire Coast Path from St Govans to the Green Bridge of Wales Elegug Stacks are situated just east of the Green Bridge of Wales sea arch. They are probably the remnants of similar sea arches, now collapsed, and formed in the upper part of the Dinantian age Carboniferous Limestone Series. There are seals visible on the sandy beach below the centre of the photo

Pembrokeshire Coast Path from St Govan's to the Green Bridge of Wales At Bullslaughter Bay, the Dinantian age Carboniferous Limestone Series has been eroded along a series of angular folds and fractures, forming a set of sea caves and sea stacks. The main structure is the Bullslaughter Bay syncline, the axis of which runs from near the caves in the centre of the photo, crossing the sandy beach towards the rocks on the right. Some of the fractures are filled with orange-brown, angular brecciated sediment ('Collapse Breccia'), thought to be of Triassic age. The flat landform topography represents the '200 foot platform' - a Tertiary age marine erosion surface. A panoramic view consisting of three portrait-style photos stitched together in Photoshop.

Pembrokeshire Coast Path from St Govans to the Green Bridge of Wales At Bullslaughter Bay, the Dinantian age Carboniferous Limestone Series has been eroded along folds and fractures into a series of sea caves and sea stacks. The main structure is the Bullslaughter Bay syncline, the axis of which runs from near the caves on the left of the photo and crosses the sandy beach. Some of the fractures are filled with orange-brown, angular brecciated sediment ('Collapse Breccia'), thought to be of Triassic age.

Pembrokeshire Coast Path from St Govans to the Green Bridge of Wales At Bullslaughter Bay, the Dinantian age Carboniferous Limestone Series has been eroded along angular folds and fractures into a series of sea caves and sea stacks. The main structure is the Bullslaughter Bay syncline, the north-dipping limb of which is visible to the right of the centre.