Ogof Marros trip 26/05/2018
Strictly speaking, this was a digging trip rather than a photography trip, but the cave really deserves a camera.
Unless otherwise stated, camera, setups, lighting, edits and gallery effects by Tarquin. Modelling and lighting at various points will be Phil Knight and Dickon Morris.
Gilman Point near Pendine, with a large Pembroke Limestone outcrop. The hill is almost a complete cross section through the limestone, showing the vertical range available at any point. To the left is the deep dry valley which drops steeply from Green Bridge.
Ragwen Point on the other side of the little Morfa Brychan bay, whose top is Twrch Sandstone (millstone grit) and whose bottom is limestone. On the right side is the pumping station.
The two beds of rock can be seen near the point; sandstone above and left, limestone below and right.
Modelling by Phil
Possible dolmen (burial tomb) on the coast.
Modelling by Phil
Morfa Brychan Rising (also known as Ragwen Point Resurgence), below the pumphouse, which has a surprisingly large amount of water (even after pumping) for such a small outcrop of limestone. The volume is similar to other big Welsh resurgences such as Ffynnon Ddu and Dan-yr-Ogof, but has almost no known caves supplying it. This picture was taken after a long dry spell.
Upstream of Green Bridge is the upper dry valley (not actually dry - small streams drain farmland into Green Bridge Cave directly below the bridge). On the right is the Milford Haven red sandstone. On the left is the limestone, dipping down to the left. In the distance, a large stream drains the sandstone, sinking almost immediately into the limestone when it makes contact with it. The valley appears to be glacial, with lots of glacial till covering the surface, making it harder for the streams to drain into the limestone.
Modelling by Dickon
Glowing red stones in the stream.
Entrance to the enormous sink crater. For scale, there is a person near the cliff on the left.
Modelling by Phil
Boat Sink, the largest of the sinks, at the left edge of the depression. The water does not seem to enter cave immediately. Instead, it sinks through the glacial till and soil into a jumble of boulders. These extend for about 15 metres to the floor of the depression. The water seems to then run through the boulders along the bottom of the depression, until it reaches the known cave.
The cliff lining the crater. The entrance to the cave is behind the cavers, with a whirlpool sink down to the left. At the end of the cliff on the right is the entrance to Phill's Folly and another small alcove, with another sink in the floor. At various points along the cliff are heavily choked openings which presumably would connect with known parts of the cave, though any connections would be extremely hard won, like the known entrance. The upstream ends of the known cave end in massive chokes some 15 metres below the cliff, and 15 metres further back from it, where the rock finally becomes stable enough to support a cave.
Modelling by Phil and Dickon
The entrance drops through a choke into Antonia's Grotto, the first substantial piece of open cave, adorned with a great deal of small formations. This is not a water-etched chamber, it is a gap above a boulder collapse. The way on is Claire's Clamber, down a slot between rocks on the left.
Antonia's Grotto.
Looking up Sciatica Shaft, part of the extensive dig through the choke. The bottom is over 20 m below the entrance.
The original breakthrough is this flat out squeeze below poised boulders. In high water, the stream almost completely fills this space, so a route was opened through the choke above instead to allow entry in all conditions.
The major breakthrough opened directly into the Wildest Dreams streamway. Almost every part of the ceiling is covered in small stalactites, quite uncommon for a British cave (well, perhaps like parts of Upper Flood Swallet), and this is how the entire cave continues.
Modelling by Phil, lighting by Tarquin and Phil
Flowstone.
Alcove.
Wildest Dreams, quite characteristic for the cave.
Modelling by Phil, lighting by Tarquin and Phil
The Fist, a leaning stalagmite in Wildest Dreams. Just up ahead, the stream flows down through rocks into Shrimp Crawl.
Modelling by Phil, lighting by Tarquin and Phil
Ceiling of Wildest Dreams, with naturally fallen stal cemented into place below the current stal.
Fallen stal in Wildest Dreams. While taking this picture, there was the painful "tinkle" of a straw snapping against a helmet. No matter how good we try to be with conservation, it is unfortunately impossible to completely avoid such events when passing through such small passages with so much stal.
Stalagmite stumps caused by repeated natural breakages, presumably as a result of flooding.
An oxbow into Crystal Carpet Chamber.
Stal in the oxbow.
The oxbow.
The oxbow. Cavers do not normally visit this oxbow at all, in order to protect the stal, but I was allowed to visit to take these pictures. The taped route ends ahead, at the window looking into Crystal Carpet Chamber. The chamber is normally visited from its other direction.
Shrimp Crawl reaches a major junction with an oxbow to the right, another way into the oxbow above, Marros Master Cave's Main Streamway ahead-right, the way on downstream ahead, Three Teir Rifts hidden up ahead-left, and the way to Crystal Carpet Chamber to the left. These stalagmites are in the entrance to Crystal Carpet Chamber.
Crystal Carpet Chamber. Cavers are asked not to enter it, so this picture was taken from the rather awkward entrance viewpoint.
The crystal carpet.
Downstream leads to Long In The Tooth Choke, the current end of the downstream cave, 33 metres below the entrance. This appears to be a choke on a fault, with the gravel floor backing up against the choke. The passage is probably quite large beneath all the gravel. Ahead are a few ways into the choke, but each ends in loose or solid choke, such as Brew Chamber and The Shark Cage. On the left just before the choke is one of the entrances to Three Tier Rifts.
Modelling by Dickon and Phil, lighting by Tarquin, Dickon and Phil
Geometric calcite crystals in Three Tier Rifts.
In one direction, Three Tier Rifts ends in parallel chokes at Falling Boulders Dig and The Chamber Of Shattered Dreams, but in the other direction is a step up into Three Tier Rifts, with its sideways stal. Nothing feels permanent here.
Modelling by Phil, lighting by Tarquin and Phil
The main passage of Three Tier Rifts, shortly before it reconnects to the streamway at the Shrimp Crawl junction.
Modelling by Phil, lighting by Tarquin and Phil
Stal in Three Tier Rifts.
Stal in Three Tier Rifts.
Stal in Three Tier Rifts.
The upper level of Three Tier Rifts starts with stal covered rocks, so to avoid these, a crawl is used. Unfortunately, this coats clothing and footware in mud, so boots must be removed to go further, and in general, cavers do not follow this passage.
Worms in the mud.
The upper passage of Three Tier Rifts.
Stal in the upper passgage.
Stal in the upper passage, which must be very carefully avoided.
The floor which must be protected.
The passage ends at an awkward squeeze up into Pillars Chamber, which has the largest stalagmites in the cave, with the taller one being nearly five feet (over 1.5 metres) high. The squeeze can be seen between rocks immediately to the left of the stalagmite. In general, cavers do not enter this chamber, and simply admire the view from the squeeze instead. This picture was taken with great care, using an automatic panorama in a tiny space, and lighting was almost impossible. The result is certainly not my best work, but it was the best I could manage in the conditions.
The passage leading onwards soon closes down (so I am told, as I did not visit), but would connect with Crystal Carpet Chamber.
The Marros Master Cave Main Streamway, the largest passage in the cave. The entire length of the large passage can be seen in this photograph.
Modelling by Phil, lighting by Tarquin and Phil
The large and beautifully decorated oxbow with high and low levels connecting with the major stream junction at Shrimp Crawl. The oxbow carries the Wildest Dreams/Shrimp Crawl stream briefly.
Modelling by Phil and Dickon, lighting by Tarquin, Phil and Dickon
Flowstone and drip pockets in the oxbow.
Drip pockets in the oxbow.
At the end of the Main Streamway, it splits into two smaller branches. This is the left branch.
Modelling by Dickon, lighting by Tarquin and Dickon
Bone in the left branch.
The branches rejoin in a chamber with a substantial choke, with a few unstable routes continuing into the choke.
Modelling by Phil and Dickon, lighting by Tarquin, Phil and Dickon
Stal in the upstream chamber.
Stal in the upstream chamber.
Stal in the upstream chamber, with what may be cryogenic fracturing. If this actually is cryogenic - as opposed to simple rock fall - then it would suggest that the cave is quite old indeed, pre-dating at least one ice age.
Exposed drip pockets in the right upstream branch.
Stal in an oxbow leading from the left branch back into the Main Streamway.
An inlet climb in the left branch previously was thought to choke, but a way on was recently found. This requires a careful wriggle under a stalagmite, passing a crystal covered oxbow back into known passage. There are so many gaps and solution tubes in this cave, it is not a surprise that a way on might be missed.
This new passage is not yet named, and I was only the fourth person to ever see it. It is another inlet, possibly from yet another sink, and has about 100 m of passage.
Modelling by Phil, lighting by Tarquin and Phil
Lichen in the inlet.
Bright rock. The red and orange stain is actually just on the surface, the rock is white.
Large larva, which appears to be a crane fly larva, in the inlet stream.
The new passage ends in a choke close to the surface, with surface debris washed in, and a substantial, loose oxbow. We were digging in a fossil outlet passage here, building the retaining wall for the digging spoil, and extracting lots of debris and a very large boulder from the dig. Further digging will be required.
Modelling by Dickon, lighting by Tarquin and Dickon
Prospecting the other entrances within the sink.
Modelling by Phil and Dickon
Beyond the end in Phil's Folly, one of the early digs in the sink crater. The draft is impressive, but almost certainly joins the known cave.
Ogof y Carreg Wen, a fragment of very large cave passage further up the valley. This probably represents an earlier sink, from when the valley was shallower.
Modelling by Phil, lighting by Tarquin and Phil
The end of Ogof y Carreg Wen's main passage, below a climb.
Modelling by Phil, lighting by Tarquin and Phil
Roof of the high level passage above the main end of Ogof y Carreg Wen, showing significant anastomosis.
Gilman Point near Pendine, with a large Pembroke Limestone outcrop. The hill is almost a complete cross section through the limestone, showing the vertical range available at any point. To the left is the deep dry valley which drops steeply from Green Bridge.
Ragwen Point on the other side of the little Morfa Brychan bay, whose top is Twrch Sandstone (millstone grit) and whose bottom is limestone. On the right side is the pumping station.
The two beds of rock can be seen near the point; sandstone above and left, limestone below and right.
Modelling by Phil
Possible dolmen (burial tomb) on the coast.
Modelling by Phil
Morfa Brychan Rising (also known as Ragwen Point Resurgence), below the pumphouse, which has a surprisingly large amount of water (even after pumping) for such a small outcrop of limestone. The volume is similar to other big Welsh resurgences such as Ffynnon Ddu and Dan-yr-Ogof, but has almost no known caves supplying it. This picture was taken after a long dry spell.
Upstream of Green Bridge is the upper dry valley (not actually dry - small streams drain farmland into Green Bridge Cave directly below the bridge). On the right is the Milford Haven red sandstone. On the left is the limestone, dipping down to the left. In the distance, a large stream drains the sandstone, sinking almost immediately into the limestone when it makes contact with it. The valley appears to be glacial, with lots of glacial till covering the surface, making it harder for the streams to drain into the limestone.
Modelling by Dickon
Glowing red stones in the stream.
Entrance to the enormous sink crater. For scale, there is a person near the cliff on the left.
Modelling by Phil
Boat Sink, the largest of the sinks, at the left edge of the depression. The water does not seem to enter cave immediately. Instead, it sinks through the glacial till and soil into a jumble of boulders. These extend for about 15 metres to the floor of the depression. The water seems to then run through the boulders along the bottom of the depression, until it reaches the known cave.
The cliff lining the crater. The entrance to the cave is behind the cavers, with a whirlpool sink down to the left. At the end of the cliff on the right is the entrance to Phill's Folly and another small alcove, with another sink in the floor. At various points along the cliff are heavily choked openings which presumably would connect with known parts of the cave, though any connections would be extremely hard won, like the known entrance. The upstream ends of the known cave end in massive chokes some 15 metres below the cliff, and 15 metres further back from it, where the rock finally becomes stable enough to support a cave.
Modelling by Phil and Dickon
The entrance drops through a choke into Antonia's Grotto, the first substantial piece of open cave, adorned with a great deal of small formations. This is not a water-etched chamber, it is a gap above a boulder collapse. The way on is Claire's Clamber, down a slot between rocks on the left.
Antonia's Grotto.
Looking up Sciatica Shaft, part of the extensive dig through the choke. The bottom is over 20 m below the entrance.
The original breakthrough is this flat out squeeze below poised boulders. In high water, the stream almost completely fills this space, so a route was opened through the choke above instead to allow entry in all conditions.
The major breakthrough opened directly into the Wildest Dreams streamway. Almost every part of the ceiling is covered in small stalactites, quite uncommon for a British cave (well, perhaps like parts of Upper Flood Swallet), and this is how the entire cave continues.
Modelling by Phil, lighting by Tarquin and Phil
Flowstone.
Alcove.
Wildest Dreams, quite characteristic for the cave.
Modelling by Phil, lighting by Tarquin and Phil
The Fist, a leaning stalagmite in Wildest Dreams. Just up ahead, the stream flows down through rocks into Shrimp Crawl.
Modelling by Phil, lighting by Tarquin and Phil
Ceiling of Wildest Dreams, with naturally fallen stal cemented into place below the current stal.
Fallen stal in Wildest Dreams. While taking this picture, there was the painful "tinkle" of a straw snapping against a helmet. No matter how good we try to be with conservation, it is unfortunately impossible to completely avoid such events when passing through such small passages with so much stal.
Stalagmite stumps caused by repeated natural breakages, presumably as a result of flooding.
An oxbow into Crystal Carpet Chamber.
Stal in the oxbow.
The oxbow.
The oxbow. Cavers do not normally visit this oxbow at all, in order to protect the stal, but I was allowed to visit to take these pictures. The taped route ends ahead, at the window looking into Crystal Carpet Chamber. The chamber is normally visited from its other direction.
Shrimp Crawl reaches a major junction with an oxbow to the right, another way into the oxbow above, Marros Master Cave's Main Streamway ahead-right, the way on downstream ahead, Three Teir Rifts hidden up ahead-left, and the way to Crystal Carpet Chamber to the left. These stalagmites are in the entrance to Crystal Carpet Chamber.
Crystal Carpet Chamber. Cavers are asked not to enter it, so this picture was taken from the rather awkward entrance viewpoint.
The crystal carpet.
Downstream leads to Long In The Tooth Choke, the current end of the downstream cave, 33 metres below the entrance. This appears to be a choke on a fault, with the gravel floor backing up against the choke. The passage is probably quite large beneath all the gravel. Ahead are a few ways into the choke, but each ends in loose or solid choke, such as Brew Chamber and The Shark Cage. On the left just before the choke is one of the entrances to Three Tier Rifts.
Modelling by Dickon and Phil, lighting by Tarquin, Dickon and Phil
Geometric calcite crystals in Three Tier Rifts.
In one direction, Three Tier Rifts ends in parallel chokes at Falling Boulders Dig and The Chamber Of Shattered Dreams, but in the other direction is a step up into Three Tier Rifts, with its sideways stal. Nothing feels permanent here.
Modelling by Phil, lighting by Tarquin and Phil
The main passage of Three Tier Rifts, shortly before it reconnects to the streamway at the Shrimp Crawl junction.
Modelling by Phil, lighting by Tarquin and Phil
Stal in Three Tier Rifts.
Stal in Three Tier Rifts.
Stal in Three Tier Rifts.
The upper level of Three Tier Rifts starts with stal covered rocks, so to avoid these, a crawl is used. Unfortunately, this coats clothing and footware in mud, so boots must be removed to go further, and in general, cavers do not follow this passage.
Worms in the mud.
The upper passage of Three Tier Rifts.
Stal in the upper passgage.
Stal in the upper passage, which must be very carefully avoided.
The floor which must be protected.
The passage ends at an awkward squeeze up into Pillars Chamber, which has the largest stalagmites in the cave, with the taller one being nearly five feet (over 1.5 metres) high. The squeeze can be seen between rocks immediately to the left of the stalagmite. In general, cavers do not enter this chamber, and simply admire the view from the squeeze instead. This picture was taken with great care, using an automatic panorama in a tiny space, and lighting was almost impossible. The result is certainly not my best work, but it was the best I could manage in the conditions.
The passage leading onwards soon closes down (so I am told, as I did not visit), but would connect with Crystal Carpet Chamber.
The Marros Master Cave Main Streamway, the largest passage in the cave. The entire length of the large passage can be seen in this photograph.
Modelling by Phil, lighting by Tarquin and Phil
The large and beautifully decorated oxbow with high and low levels connecting with the major stream junction at Shrimp Crawl. The oxbow carries the Wildest Dreams/Shrimp Crawl stream briefly.
Modelling by Phil and Dickon, lighting by Tarquin, Phil and Dickon
Flowstone and drip pockets in the oxbow.
Drip pockets in the oxbow.
At the end of the Main Streamway, it splits into two smaller branches. This is the left branch.
Modelling by Dickon, lighting by Tarquin and Dickon
Bone in the left branch.
The branches rejoin in a chamber with a substantial choke, with a few unstable routes continuing into the choke.
Modelling by Phil and Dickon, lighting by Tarquin, Phil and Dickon
Stal in the upstream chamber.
Stal in the upstream chamber.
Stal in the upstream chamber, with what may be cryogenic fracturing. If this actually is cryogenic - as opposed to simple rock fall - then it would suggest that the cave is quite old indeed, pre-dating at least one ice age.
Exposed drip pockets in the right upstream branch.
Stal in an oxbow leading from the left branch back into the Main Streamway.
An inlet climb in the left branch previously was thought to choke, but a way on was recently found. This requires a careful wriggle under a stalagmite, passing a crystal covered oxbow back into known passage. There are so many gaps and solution tubes in this cave, it is not a surprise that a way on might be missed.
This new passage is not yet named, and I was only the fourth person to ever see it. It is another inlet, possibly from yet another sink, and has about 100 m of passage.
Modelling by Phil, lighting by Tarquin and Phil
Lichen in the inlet.
Bright rock. The red and orange stain is actually just on the surface, the rock is white.
Large larva, which appears to be a crane fly larva, in the inlet stream.
The new passage ends in a choke close to the surface, with surface debris washed in, and a substantial, loose oxbow. We were digging in a fossil outlet passage here, building the retaining wall for the digging spoil, and extracting lots of debris and a very large boulder from the dig. Further digging will be required.
Modelling by Dickon, lighting by Tarquin and Dickon
Prospecting the other entrances within the sink.
Modelling by Phil and Dickon
Beyond the end in Phil's Folly, one of the early digs in the sink crater. The draft is impressive, but almost certainly joins the known cave.
Ogof y Carreg Wen, a fragment of very large cave passage further up the valley. This probably represents an earlier sink, from when the valley was shallower.
Modelling by Phil, lighting by Tarquin and Phil
The end of Ogof y Carreg Wen's main passage, below a climb.
Modelling by Phil, lighting by Tarquin and Phil
Roof of the high level passage above the main end of Ogof y Carreg Wen, showing significant anastomosis.