There and Back Again, New Zealand
Eight members of the Imperial College Caving Club went to the South Island of New Zealand for three weeks on an expedition to find new caves. Due to high winds and early snowfall, the original plan to base ourselves on Mt Owen had to be abandoned, and the expedition relocated to the Takaka Hills, a lower series of mountains in the same marble region as Mt Owen. With just over two weeks in the field, the expedition found new passage deep in an already discovered cave (Ed’s Cellar) as well as finding several new caves (Weta than Ever, Black Helix and Red Dog/Dead Rogue) in the Canaan Downs region. These caves were surveyed to BCRA Grade 5.
Initially we were based around the Nelson Speleological Group’s mountain hut. There is thick forest to the NE, which gives way to a marble outcropping and a sharp ridge which curves around the forest filled depression below. This forest in turn gives way to open meadows and broken surface karst to the S and SW. Most caves that we found were cracks in an outcrop of karst. Our most significant find was a 40 m muddy surface shaft which died at a muddy choke.
This area lies to the north of the first campsite. It is open grassland and pasture, with fences and some farm buildings. The valley rises on either side, broken by large rocks and with shrubs and trees. Past the farmhouses, an abandoned creek meets with an active river at the foot of Ed’s Cellar hill. The entrance to the cave proper lies in a rock fall on the hillock.
Ed’s Cellar: This well known cave was last surveyed in 1962, we pushed a lead down through the Razorblades near Grannies Grotto. Many people had been this way, as evidenced by mud on the flowstone, but we believe we are the first to descend ‘Head on Over’ to the sandy crawl where the leads terminates. A full survey from the entrance down to our pushing front is reproduced below the last section is grade 1, but a full grade 5 survey is being drawn up.
This area is to the north west of Canaan Downs campsite and can be reached by following the road onwards to Harwood’s Hole before following the trail west. Gold creek meanders through tussocky grass land and is itself surrounded by trees. Two known caves, Corkscrew and Marble pot are located in this region. The area was systematically searched for cave, yielding Black Helix.
Black Helix: Black Helix cave is 40 m long and 25 m deep. It opens up as a steeply slopingplane covered with rubble and unstable boulders. Ten metres on it splits laterally, only to rejoin after a short drop. Various squeezes and more drops lead to the final rift, narrowing onwards to an impassable crack. Rodent bones are found in this terminal chamber.
Directly to the north of a house owned by “Bob the Texan” (and due south of the Canaan Downs camp) is a dry gully in a large grass meadow, where alpacas are grazed. Bob told us that during heaving rain water disappeared under the large rocks the sat in the gully. The rocks sit on a bed of thick red mud. Several leads were pursued under the largest boulder, which we named Bob’s Tomo:
Here Hare Here: On the north face of the boulder, a tight passage lead horizontally whilst another passage lead down. Removing boulders from the lower passage lead to an upwards slope that connected both passages. Light was visible from the other side of the boulder, but the passage didn’t seem to lead anywhere.
Bob’s Cellar: On the south side of the boulder are two passages, tucked away on the left. The obvious right hand passage leads to a small chamber which leads off into a silt filled passage too tight for a human. The left hand passage is an awkward crawl into a muddy chamber with a boulder choke in the floor. These boulders were split and moved, revealing a 3m shaft that died in a boulder choke.
Bob’s forest is mixed forest, principally alpine on the south faces of gullies, but temperate rainforest with palms on the sun facing north faces. The forest is often extremely thick and tough going, though the area directly west of Bob’s house is open and lightly forested. The forest is punctuated with large, sloping marble pavements, split by deep chasms. There are frequent depressions, some only metres from each other, all with a large, house sized boulders. We investigated dozens of these with the exception of Weta than Ever, the route the water must take chokes in mud, silt and debris within a few metres.
Weta than Ever: A large collection of boulders in a depression at the end of a dry river bed hides a deep rift which was descended to reveal a linear cave that pushed due west along what was presumably a fracture in the marble. The cave eventually closes down and ends in a silty sump. There is a large population of cave wetas in the
This creek is unnamed on our map, but a short walk south of Canaan Downs leads to the forest opening up to the east, revealing a dry creek bed. The creek bed is not made up of karstic rocks, but instead appears to contain granite from the intrusion to the south. There are plentiful flood sinks on either side of the river, and the land rises to form cliff faces along the active streamway further east. The active and dry streamways meet (both sloping downhill), with the active streamway sinking close by to the north. Further up the active streamway the stream meanders around a large rock which contains Red Dog in a lush grassy valley with woodland on either side.
Sinking Ship Sink: The active streamway sinks into two sinks. The left hand sink is a boulder choke with a large passage through. Inside the cave is one large boulder choke which can be navigated to a small waterfall that sinks into the floor of a small chamber. The passage clearly leads on to the left under a tight boulder choke, but we were unable to remove enough boulders to allow us to progress. Most, but not probably not all, of the water that sinks on the surface seems to end up in this waterfall.
Red Dog/Dead Rogue: Red Dog is a large chamber accessible through several entrances on the side of a cliff overlooking the active stream. The chamber has a thick layer of mud on the floor and a great deal of debris, indicating that water fills the chamber during flood conditions. There are multiple passages on through shattered boulders. We followed and enlarged many of these passages, occasionally emerging in the sunlight again by another entrance (such as Dead Rogue), but we were unable to find a route that consistently went up or down. The rock does not appear to be shaped by water, but was instead formed by the collapse of a huge rock which had many calcite infilled fractures. Our search for onward routes was thorough but not exhaustive. A grade 5 survey is being drawn up.
Text: Rhys Tyers