Palmerston Cave July 3

A short walk across paddocks, up a hill, along a farm track and into a valley led to Palmerston Cave, Otago's only known marble cave. The valley is mostly grassy hillsides but the marble bluffs are typically guarded by remnants of broadleaf bush with impressive bushlawyer in places. The rather impressive entrance is perfectly hidden by a broadleaf tree. A scree slope leads down into the well-lit main chamber floored with breakdown boulders. Bones found in this cave include many extinct or rare birds including kiwi, kereru, kakapo, laughing owl and several species of moa. The side passage to the north requires a bit of crawling to reach a small room. The side passage to the south at the back of the cave leads to graffiti (dating to 1929) and a moderately amusing 3.5m climb up old flowstone where another short but greasy climb led to more graffiti and a convincing end.

Walking a short distance down the dry streambed from Palmerston Cave, one is abruptly bombarded by the sound of water. Two very sizable springs are encountered filtering between large marble boulders. Just below this point, the formerly-dry creekbed is now restored to its correct flow. Just up the hillside from the springs, a downward sloping leaf-litter pancake entrance with a bedrock roof was rediscovered and entered. This second cave is about 40m long with a few small side passages. The passage morphology and scallops on the walls suggest this was formerly a stream passage emerging from the hillside. A vertical squeeze near the entrance leads to a small room where the stream rises up through breakdown into a calm pool which probably drains out to the springs. Almost got my feet wet here!

Palmerston Cave seems to be a former submergence of the creek with the small resurgence cave being a part of the same system. The present day creek must sink into marble underlying its bed, (possibly several kilometers upstream of Palmerston Cave) flow directly underneath the cave and emerge more or less directly underneath its former resurgence. Sadly, the current karst system may be too youthful to enter. We continued walking down the creek to have a look at the marble downstream. While marble was abundant and we saw a sizable karst spring with a concrete weir marked “Blue Bell 1910,” no entrances were found. While karst features are few and much of the marble is visible, all it takes is one bush or tree to hide a cave.

Photo by Lara