Slaughter Stream Cave Flow Choke trip 30/06/2021
Unless otherwise stated, camera, setups, lighting, edits and gallery effects by Tarquin. Modelling and lighting at various points will be Mark Tringham, Jann Padley and Judi.
This was a surveying trip aimed at part of Flow Choke Passage. I have already covered the route into this area in a previous gallery.
We started our survey just after Vittals Stop, at the junction with Connection Crawl. Once again, Mark is leading the surveying.
Modelling by Mark, lighting by Tarquin and Mark
Surveying at the start of Flow Choke Passage. Though the older survey does not show a point where the name changes, the early cave descriptions call it "Flow Choke Passage" from Vittals Stop onwards.
Modelling by Jann, lighting by Tarquin and Jann
A beautifully shaped section of passage, reminiscent of an SR-71 blackbird. Now you know where they got the design from.
Modelling by Judi, lighting by Tarquin and Judi
Admiring some stylolites on the ceiling. These are formed where the pressure during rock formation caused a section of limestone (actually dolomite in this area) to dissolve, leaving behind only the non-soluble clay that was mixed in with the limestone. The clay here is various shades of purple. Stylolites can normally be seen as a wiggly horizontal line on the wall, but when a chunk of rock falls off the ceiling, it can be exposed as a series of spikes, since it wiggles in two dimensions.
Modelling by Judi, lighting by Tarquin and Judi
A phreatic tube section passing Small Oxbow.
Modelling by Judi, lighting by Tarquin and Judi
Small Oxbow.
Modelling by Judi, lighting by Tarquin and Judi
Flow Choke Passage then intersects at a branching fault, creating a chamber.
Modelling by Judi, Jann and Mark, lighting by Tarquin, Judi, Jann and Mark
This very obvious fault breccia is in the ceiling.
A side rift following the fault, which seems to end very quickly. This ascends a set of dangerously poised rocks, and does not look safe to enter any further than I did, but someone has indeed been further in.
The admirable passage following the chamber.
Modelling by Judi, lighting by Tarquin and Judi
Lowering to a bedding plane.
Modelling by Jann, lighting by Tarquin and Jann
And then a ribbed tube.
Modelling by Jann and Mark, lighting by Tarquin Jann and Mark
Solution holes at the junction with Large Oxbow.
Modelling by Tarquin
After the junction with Hull Passage, Flow Choke Passage temporarily becomes a little shattered.
Modelling by Judi, lighting by Tarquin and Judi
A sudden increase at the largest chamber in the cave. This shows lots of evidence of freeze-thaw action, and the original passage shape is no longer visible. It would not look out of place in Draenen.
Modelling by Judi, lighting by Tarquin and Judi
The floor has a liberal sprinkling of cryostal - the white pieces on the rocks. This theme is repeated for the rest of the passage. It really needs to be taped off properly.
Lighting by Tarquin and Judi
A large coral fossil on the hairpin bend beyond the chamber. This is likely to be a Syringopora (more closely related to smooth walled Favosites than to the ribbed walled Lithostrotion).
Modelling by Mark, lighting by Tarquin and Mark
The hairpin bend rift.
Lighting by Tarquin, Mark and Judi
Impressively tall rift.
Modelling by Jann and Judi, lighting by Tarquin, Jann and Judi
The rift floor has more cryostal, but most of it is not taped. There was clearly an effort to preserve some of it with bang wire, but it needs a proper tape around the rest
The last section of passage before Large Oxbow rejoins, where our survey temporarily ended. We then made a rapid trip up to Flow Choke and back.
Modelling by Judi, lighting by Tarquin and Judi
Start of Hull Passage, where our survey resumed.
Modelling by Judi, lighting by Tarquin, Judi and Mark
Fossil dorsal spine of a proto-shark in Hull Passage, similar to the ones seen in Draenen. The direction of the lines shows that it is almost certainly a Ctenacanthus dorsal spine, with only the tip being visible, rather than the classic U-shaped cross section seen further down the bone. About 5 cm protrudes from the wall, but the bone would have originally been about 25-30 cm long in total. This is a particularly well preserved specimen, and was the only one that we saw in the cave.
Climbing up through Roadside Choke.
Modelling by Judi, lighting by Tarquin
Over the top of the choke is a large fault chamber.
Modelling by Jann, lighting by Tarquin and Jann
Very visible slickensides - scratch lines - on the wall of the chamber (just in front of his hands), showing the fault moved laterally; a strike-slip fault.
Modelling by Judi and Mark, lighting by Tarquin, Judi and Mark
At this end, the passage just pinches out.
Even more visible slickensides at the other end of the chamber. At this end is a choke, which is a possible way that Norman the dog got in here, after entering through a coal mine above.
Modelling by Judi, lighting by Tarquin and Judi
Climbing down out of the fault chamber into the continuation of Hull Passage.
Modelling by Jann and Judi, lighting by Tarquin, Jann, Judi and Mark
The continuing rift of Hull Passage.
Modelling by Judi and Mark, lighting by Tarquin, Judi and Mark
Hull Passage.
Modelling by Judi and Mark's legs, lighting by Mark
Above the first dip in the floor.
Modelling by Judi and Mark's hand, lighting by Tarquin, Judi and Mark
Downward Dog, the vertical squeeze down into Dog's Grave Passage, creating the smaller round trip. We closed the loop with only a small error in the survey, enough to claim grade 6 if desired, and consistent with the grade of the larger round trip that had been done previously.
Modelling by Jann, lighting by Tarquin and Jann
Hull Passage continues the same, eventually choking. There is another patch of cryostal just after Downward Dog, which is unexpected here, as there is almost no other sign of permafrost action.
Modelling by Jann, lighting by Tarquin and Jann
Cracked mud in Hull Passage.
Flecks of crystalline deposit on the wall of Hull Passage. This appears to be the remains of redissolved calcite.
We started our survey just after Vittals Stop, at the junction with Connection Crawl. Once again, Mark is leading the surveying.
Modelling by Mark, lighting by Tarquin and Mark
Surveying at the start of Flow Choke Passage. Though the older survey does not show a point where the name changes, the early cave descriptions call it "Flow Choke Passage" from Vittals Stop onwards.
Modelling by Jann, lighting by Tarquin and Jann
A beautifully shaped section of passage, reminiscent of an SR-71 blackbird. Now you know where they got the design from.
Modelling by Judi, lighting by Tarquin and Judi
Admiring some stylolites on the ceiling. These are formed where the pressure during rock formation caused a section of limestone (actually dolomite in this area) to dissolve, leaving behind only the non-soluble clay that was mixed in with the limestone. The clay here is various shades of purple. Stylolites can normally be seen as a wiggly horizontal line on the wall, but when a chunk of rock falls off the ceiling, it can be exposed as a series of spikes, since it wiggles in two dimensions.
Modelling by Judi, lighting by Tarquin and Judi
A phreatic tube section passing Small Oxbow.
Modelling by Judi, lighting by Tarquin and Judi
Small Oxbow.
Modelling by Judi, lighting by Tarquin and Judi
Flow Choke Passage then intersects at a branching fault, creating a chamber.
Modelling by Judi, Jann and Mark, lighting by Tarquin, Judi, Jann and Mark
This very obvious fault breccia is in the ceiling.
A side rift following the fault, which seems to end very quickly. This ascends a set of dangerously poised rocks, and does not look safe to enter any further than I did, but someone has indeed been further in.
The admirable passage following the chamber.
Modelling by Judi, lighting by Tarquin and Judi
Lowering to a bedding plane.
Modelling by Jann, lighting by Tarquin and Jann
And then a ribbed tube.
Modelling by Jann and Mark, lighting by Tarquin Jann and Mark
Solution holes at the junction with Large Oxbow.
Modelling by Tarquin
After the junction with Hull Passage, Flow Choke Passage temporarily becomes a little shattered.
Modelling by Judi, lighting by Tarquin and Judi
A sudden increase at the largest chamber in the cave. This shows lots of evidence of freeze-thaw action, and the original passage shape is no longer visible. It would not look out of place in Draenen.
Modelling by Judi, lighting by Tarquin and Judi
The floor has a liberal sprinkling of cryostal - the white pieces on the rocks. This theme is repeated for the rest of the passage. It really needs to be taped off properly.
Lighting by Tarquin and Judi
A large coral fossil on the hairpin bend beyond the chamber. This is likely to be a Syringopora (more closely related to smooth walled Favosites than to the ribbed walled Lithostrotion).
Modelling by Mark, lighting by Tarquin and Mark
The hairpin bend rift.
Lighting by Tarquin, Mark and Judi
Impressively tall rift.
Modelling by Jann and Judi, lighting by Tarquin, Jann and Judi
The rift floor has more cryostal, but most of it is not taped. There was clearly an effort to preserve some of it with bang wire, but it needs a proper tape around the rest
The last section of passage before Large Oxbow rejoins, where our survey temporarily ended. We then made a rapid trip up to Flow Choke and back.
Modelling by Judi, lighting by Tarquin and Judi
Start of Hull Passage, where our survey resumed.
Modelling by Judi, lighting by Tarquin, Judi and Mark
Fossil dorsal spine of a proto-shark in Hull Passage, similar to the ones seen in Draenen. The direction of the lines shows that it is almost certainly a Ctenacanthus dorsal spine, with only the tip being visible, rather than the classic U-shaped cross section seen further down the bone. About 5 cm protrudes from the wall, but the bone would have originally been about 25-30 cm long in total. This is a particularly well preserved specimen, and was the only one that we saw in the cave.
Climbing up through Roadside Choke.
Modelling by Judi, lighting by Tarquin
Over the top of the choke is a large fault chamber.
Modelling by Jann, lighting by Tarquin and Jann
Very visible slickensides - scratch lines - on the wall of the chamber (just in front of his hands), showing the fault moved laterally; a strike-slip fault.
Modelling by Judi and Mark, lighting by Tarquin, Judi and Mark
At this end, the passage just pinches out.
Even more visible slickensides at the other end of the chamber. At this end is a choke, which is a possible way that Norman the dog got in here, after entering through a coal mine above.
Modelling by Judi, lighting by Tarquin and Judi
Climbing down out of the fault chamber into the continuation of Hull Passage.
Modelling by Jann and Judi, lighting by Tarquin, Jann, Judi and Mark
The continuing rift of Hull Passage.
Modelling by Judi and Mark, lighting by Tarquin, Judi and Mark
Hull Passage.
Modelling by Judi and Mark's legs, lighting by Mark
Above the first dip in the floor.
Modelling by Judi and Mark's hand, lighting by Tarquin, Judi and Mark
Downward Dog, the vertical squeeze down into Dog's Grave Passage, creating the smaller round trip. We closed the loop with only a small error in the survey, enough to claim grade 6 if desired, and consistent with the grade of the larger round trip that had been done previously.
Modelling by Jann, lighting by Tarquin and Jann
Hull Passage continues the same, eventually choking. There is another patch of cryostal just after Downward Dog, which is unexpected here, as there is almost no other sign of permafrost action.
Modelling by Jann, lighting by Tarquin and Jann
Cracked mud in Hull Passage.
Flecks of crystalline deposit on the wall of Hull Passage. This appears to be the remains of redissolved calcite.