Album Pembrokeshire from Earthwatcher

Thrust fault in Coal Measures at Amroth, Pembrokeshire

nobody@ipernity.com (Earthwatcher) — Mon, 18 Dec 2006 23:52:56 +0000

Originally posted for the Guesswhere UK group

Thrust fault and related compressional structures in Coal Measures in the cliffs just west of Amroth, Pembrokeshire, west Wales.

See where this picture was taken. [?]

Ladies Cave Anticline

nobody@ipernity.com (Earthwatcher) — Wed, 27 Dec 2006 07:12:45 +0000

Earthwatcher has posted:

Just south of Saundersfoot, Pembrokeshire.
Scanned from a 35mm transparency, taken with a Zenit 'E' camera.

Manorbier Bay, west Wales

nobody@ipernity.com (Earthwatcher) — Fri, 29 Dec 2006 08:25:52 +0000

Earthwatcher has posted:

Manorbier Bay, looking west. The wave-cut platform consists of vertically bedded Old Red Sandstone.

Taken from the Pembrokeshire Coast Path at the height of the foot & mouth disease crisis, when only limited sections of the footpath were open.

Recumbent fold near Little Haven, Pembrokeshire, west Wales

nobody@ipernity.com (Earthwatcher) — Mon, 04 Jun 2007 13:07:14 +0000

Earthwatcher has posted:

This photo shows the cliffs in the small sandy bay known as The Settlands between Little Haven and Broad Haven in Pembrokeshire, west Wales.

The rocks here are Upper Carboniferous Coal Measures and are part of the western extremity of the Pembrokeshire coalfield. The strata have been severely deformed by compressional tectonics during the Hercynian (Variscan) earth movements. In the centre of the photograph the rocks are folded into a recumbent fold, with the axis near horizontal - a sort of tilted " < " shape. A thrust fault separates this fold from the steeply dipping, inverted rocks on the LH side. These form the headland known as The Rain.

Scanned from a Kodachrome 64 transparency.

Goskar Rock, North Beach, Tenby

nobody@ipernity.com (Earthwatcher) — Mon, 24 Sep 2007 17:04:29 +0000

Earthwatcher has posted:

Originally uploaded for the Guesswhere UK group.
Goskar Rock is a prominent feature of the North Beach at Tenby, Pembrokeshire. Comprised of Namurian age sandstones and siltstones, this is a great locality for teaching students to measure the dip (angle of slope) and strike (level course bearing) of the rocks.

Folding at Monkstone Point, near Saundersfoot, Pembrokeshire

nobody@ipernity.com (Earthwatcher) — Sat, 24 Nov 2007 14:00:02 +0000

Earthwatcher has posted:

Originally uploaded for the Guesswhere UK group.

Complex folding in Namurian rocks at Monkstone Point near Saundersfoot, Pembrokeshire, in the bottom left-hand corner of Wales.

This is a complex anticlinal chevron fold. The main limbs of the fold are the straight parts, dipping at 40° to the south (L) and 30° to the north (R).

One feature of tight folds like this is the SPACE problem. The rocks in the central part of the fold get compressed as the available volume they have to occupy reduces as the folding progresses. This leads to all sorts of seemingly chaotic deformation of the stuff in the middle. In this instance, the core of the fold is comprised of thin beds of sandstone interleaved with thin soft shale layers. The latter especially has deformed almost plasticly under the compressional stresses, and the thin sandstones also to a lesser extent. This results in the incompetent deformation structures seen in the photo, to accommodate the reduced space available in the core of the fold.

Ynys Penpleidiau, Pembrokeshire

nobody@ipernity.com (Earthwatcher) — Fri, 19 Sep 2008 07:21:43 +0000

Earthwatcher has posted:

This is a view on a blusterous day from the Caerfai cliff fort near St David's, Pembrokeshire, looking south over the tiny island of Penpleidiau and St Bride's Bay. Skomer and Midland Island are just visible on the centre skyline.

Pillow lavas on Strumble Head, Pembrokeshire

nobody@ipernity.com (Earthwatcher) — Fri, 19 Sep 2008 07:30:21 +0000

Earthwatcher has posted:

This is a view of the Ordovician age pillow lavas on Strumble Head, Pembrokeshire.
Pillow lavas are formed when molten basalt lava is erupted onto the sea floor. If the water is deep enough, the hydrostatic pressure stops the lava from exploding the sea water into steam. Instead, the liquid rock and liquid water co-exist together in an uneasy truce. The lava is extruded like toothpaste into successive oval globules, resembling pillows or sacks, hence the name. See the video clip here:

oceanexplorer.noaa.gov/explorations/04fire/background/vol...

Carn Llidi, Pembrokeshire

nobody@ipernity.com (Earthwatcher) — Mon, 22 Sep 2008 14:40:24 +0000

Earthwatcher has posted:

Originally posted fro the Guesswhere UK group.
This is a view of Carn Llidi, a tor-like miniature mountain (181 m) of gabbro, overlooking St David's, Pembrokeshire. The photo was taken from the Iron Age cliff fort on St David's Head.

Carn Llidi summit

nobody@ipernity.com (Earthwatcher) — Tue, 23 Sep 2008 06:43:12 +0000

Earthwatcher has posted:

The final rock dome on the summit of Carn Llidi (181 m elevation).
It looks a fairly easy scramble here, but in the high wind conditions at the time of taking this photo, I decided against going up the last awkward bit. I had a job keeping still enough to take the photos. :-(

This is a panorama composed of two photos, joined using Canon's Photostich software.
Best viewed large.

Carn Llidi from Coetan Arthur

nobody@ipernity.com (Earthwatcher) — Tue, 23 Sep 2008 06:58:43 +0000

Earthwatcher has posted:

This is a view of Carn Llidi, a tor-like miniature mountain (181 m) comprised of gabbro, overlooking St David's, Pembrokeshire. The photo was taken from near the Neolithic burial chamber Coetan Arthur ('Arthur's Quoit') near St David's Head.

I was struck by the colourful rocks and moorland in the late afternoon sun, after the earlier blustery rain.

Warm rocks and Carn Llidi

nobody@ipernity.com (Earthwatcher) — Tue, 23 Sep 2008 07:00:11 +0000

Earthwatcher has posted:

Whitesands Bay from Carn Llidi

nobody@ipernity.com (Earthwatcher) — Tue, 23 Sep 2008 07:01:37 +0000

Earthwatcher has posted:

A southwesterly view from close to the summit of Carn Llidi, a tor-like miniature mountain (181 m) comprised of gabbro, overlooking St David's, Pembrokeshire.

Whitesands Bay / Porth Mawr and Ramsey Island are visible in the upper right.

Coetan Arthur and Carn Llidi

nobody@ipernity.com (Earthwatcher) — Tue, 23 Sep 2008 07:02:38 +0000

Earthwatcher has posted:

Coetan Arthur ('Arthur's Quoit') is a Neolithic burial chamber near St David's Head, Pembrokeshire. Carn Llidi, a tor-like miniature mountain (181 m) comprised of gabbro, is visible in the distance. One theory is that the capstone of Coetan Arthur was deliberately aligned to mimic the outline of Carn Llidi. Who knows?

Coetan Arthur and boulder field

nobody@ipernity.com (Earthwatcher) — Tue, 23 Sep 2008 07:04:02 +0000

Earthwatcher has posted:

Coetan Arthur ('Arthur's Quoit') is a Neolithic burial chamber near St David's Head, Pembrokeshire.

Whitesands Bay / Porth Mawr and Ramesey Island are in the background.

Coetan Arthur

nobody@ipernity.com (Earthwatcher) — Tue, 23 Sep 2008 07:04:41 +0000

Earthwatcher has posted:

Close-up view of Coetan Arthur ('Arthur's Quoit'), a Neolithic burial chamber near St David's Head, Pembrokeshire.

Whitesands Bay / Porth Mawr is in the background.

Cliff Fort rampart and ditch, St David's Head

nobody@ipernity.com (Earthwatcher) — Tue, 23 Sep 2008 07:05:59 +0000

Earthwatcher has posted:

A view of the rampart and ditch of the Iron Age cliff fort at St David's Head, Pembrokeshire. Ramsey Island is visible in the distance.

Point St John, Whitesands Bay

nobody@ipernity.com (Earthwatcher) — Tue, 23 Sep 2008 07:09:11 +0000

Earthwatcher has posted:

Point St John is the westerly headland on the south side of Whitseands Bay / Porth Mawr, Pembrokeshire.

I was intrigued by the steeply dipping bedding planes of Cambrian sediments, wet and glistening in the afternoon sun after a sharp shower had passed over.

Trwynhwrddyn and Whitesands Bay

nobody@ipernity.com (Earthwatcher) — Tue, 23 Sep 2008 07:10:52 +0000

Earthwatcher has posted:

Blustery conditions in Whitesands Bay / Porth Mawr, viewed from the coastal path leading to St David's Head, Pembrokeshire.

The narrow peninsula is Trwynhwrddyn ('Ram's Nose'), comprised of steeply dipping uppermost Cambrian and basal Ordovician shales and tuffs.

Trwynhwrddyn

nobody@ipernity.com (Earthwatcher) — Tue, 23 Sep 2008 07:11:48 +0000

Earthwatcher has posted:

Blustery conditions in Whitesands Bay / Porth Mawr, viewed from the coastal path leading to St David's Head, Pembrokeshire.

The headland in the foreground is Trwynhwrddyn ('Ram's nose') - a narrow peninsula comprised of steeply dipping uppermost Cambrian and basal Ordovician shales and tuffs.

The hills in the distance are on Ramsey Island.