Earthwatcher's photos with the keyword: Telpyn Point Sandstone

Druidston Haven geology: Cliff Section 6 interpretation Interpretation No.6 of a series of six photos and interpretations to illustrate the geology of Druidston Haven, Pembrokeshire. The cliffs of Druidston Haven mostly consist of Ordovician (Caradocian) age shales with some thin sandstones. During the Caledonian orgogeny at the end of the Silurian period, these were deformed into a series of mostly upright open folds. These were then re-folded by Variscan movements at the end of Carboniferous, to become largely recumbent (near horizontal) or partly inverted, facing down towards the south. The Ordovician rocks form a horst - a ridge or block of strata faulted against younger rocks on either side. The Druidston Horst is bounded by the South Druidston Boundary Fault at the south end of the Haven, and the North Druidston Boundary Fault at the north end. This photo shows the southern end of the horst, terminated by the Southern Boundary Fault; a significant structure with a throw (displacement) of at least 1500 metres to the south, bringing Namurian 'Millstone Grit Series' (upper Carboniferous) rocks into contact with the Ordovician shales.

Druidston Haven geology: Cliff Section 6 Photo No.6 of a series of six photos and interpretations to illustrate the geology of Druidston Haven, Pembrokeshire. The cliffs of Druidston Haven mostly consist of Ordovician (Caradocian) age shales with some thin sandstones. During the Caledonian orgogeny at the end of the Silurian period, these were deformed into a series of mostly upright open folds. These were then re-folded by Variscan movements at the end of Carboniferous, to become largely recumbent (near horizontal) or partly inverted, facing down towards the south. The Ordovician rocks form a horst - a ridge or block of strata faulted against younger rocks on either side. The Druidston Horst is bounded by the South Druidston Boundary Fault at the south end of the Haven, and the North Druidston Boundary Fault at the north end. This photo shows the southern end of the horst, terminated by the Southern Boundary Fault; a significant structure with a throw (displacement) of at least 1500 metres to the south, bringing Namurian 'Millstone Grit Series' (upper Carboniferous) rocks into contact with the Ordovician shales.

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.

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.

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.