Mt. Field National Park traverses one of Tasmania’s most significant Karst areas – the Junee Florentine (JF) Karst, which covers an area of about 18,500 ha and contains more then 500 documented cave entrances, including many of Australia’s deepest caves. The western part of the park and the Junee Cave State Reserve are located within the karst catchment and contain numerous significant karst features of high geoconservation value. State forest adjacent to the park and reserves also contains significant caves and karst features, including caves linked to the Junee River master system, which resurge at Junee Cave near the town of Maydena. The expedition base was located in the “Left of Field” camp ground, about 10km North East of Maydena, near the entrance to Mt. Field National Park.
Good relations had been developed with some local JF cavers over the years by the team, and these local cavers kindly agreed to collaborate in sharing local knowledge, maps, coordinates etc. in return for shared information on any expedition findings to progress the potential of the region. Several local cavers also joined the expedition at various times, with a total of 21 cavers participating in the expedition in total. Overall, the expedition was welcomed by local cavers with the assistance in unlocking more cave passage in the area.
Thanks to good relationships with local Cavers, information was shared on some potential leads and areas of interest for discovery. With many of the leads described as “character building”, it gave the team a good indication that the caving would be just like home, and discoveries would not be easily won! The leads were prioritised and the team split up into a number of groups on a daily basis to pursue various exploration or reconnaissance projects, described below.
JF-40 is a short cave situated close to the large caves of Kazad-Dum and Splash Pot and was expected to connect to the remotest reaches of Splash Pot via a draughting dig. Two exploration trips resulted in approximately 40m of new passage discovered but no further connections to Splash Pot. The whole cave was resurveyed to 196m.
JF380 is located at the head of the Serendipity valley, the last cave in the Benson and Hedges series. It is a 20m deep strongly draughting hole which was thought to require some capping to progress, and expected to add about 40 m depth to Dissidence if it connected at the downstream end. Two digging trips resulted in an extension of 10m once a draughting constriction was passed, only to find the draught disappearing up an Aven and the onward route too tight to progress.
JF232 – Udensala
Udensala is a 182m deep cave developed along a steeply inclined joint. The interest in this cave lay in its position midway between Burning down the House and Porcupine Pot. Given that a large conduit must exist between these two caves, there was the possibility that a westward extension of Udensala would intercept this conduit. Two exploratory trips resulted in no new finds, but the cave was resurveyed completely to 212m.
JF210 – Sesame
The team mounted four trips into Sesame to assist with a dive project at the sump at the distant end of the cave. The cave is of interest due to its close proximity to the downstream end of the Niggly Cave master cave. It is thought that a push by divers could intersect the main drain just downstream of the terminal rock pile in Niggly. Water levels prohibited initial exploration progress by the team, but a climb was pushed and a viable bypass to a low wet section was surveyed to 80m, aiming to reduce the effort by cavers to get to Sump in future.
JF354 – Benson & Hedges & Hole 7
The Benson and Hedges series contains about 20 short potholes on the Eastern side of the Serendipity valley. Two large team trips were mounted, dividing into smaller teams on the surface due to the close proximity of the pots for exploration. Hole number 7 in the B&H series resulted in 15m of new passage being surveyed.
JF398 – Boulder Jenga
Boulder Jenga, so called due to the large and loose boulders that create the fabric of the cave. Strategically important due to the likelihood of connecting into Growling Swallet, and the large amount of water that sinks into it. Waiting for the water levels to decrease, three trips were undertaken. On the first trip, the team dug through several parts of the choke to gain the way on. On the second trip a large boulder slipped several meters and narrowly missed one of the cavers but trapped their tackle sack at the top of a climb. On the final pushing and derigging trip, a large ~150KG boulder and several others fell several meters near the team, landed on top of one of the squeezes and blocked the way on. 130m of new cave discovered.
JF293 – Whistler
Whistler acquired its name due to a howling draught in the entrance, and is located on the Eastern side of the Serendipity valley, without any theoretical connections to nearby caves. Claiming the largest input of effort from the Expedition team, seven trips, mostly capping to widen the worst of the constrictions, pushed a very tight and cold rift to add 140m of depth and 280m of surveyed passage to the cave. The cave was not pursued to its conclusion due to time restrictions; but is expected to connect into a chamber at the end of Flick Mints hole.
JF388 – Lost Pot
Five trips were made into Lost pot, not necessarily by design but rather because of unplanned events. Located in the Serendipity valley, and known for a picturesque 70m pitch, it was expected to connect into Serendipity cave itself, possibly through a draughting rockpile at the bottom of a Iron Anniversary, a 40m pitch. Overall 30m of new passage was found, but options for ongoing progression have not been fully exhausted. The cave was also fully resurveyed to 251m.
JF484 – Hot Prospect
JF-236 Bunyips Lair is a large sink found 300m east along the contour from Niggly Cave. Hot Prospect, so named due to the high hopes of the original explorers, notably due to its proximity to Niggly, one of Australia’s deepest caves. The cave is located 25m West of Bunyips layer. The original explorers only progressed a short distance inside the entrance. After the initial recce by the 2018 expedition team, subsequent trips dug through a number of constrictions to add 155m of passage and a depth of 65m. An ongoing lead through a very tight rift is viable but would require widening.
Prospecting trips were undertaken to a number of areas, targeted specifically based on potential for cave discovery along the Limestone contact. Two significant discoveries included “Hot Prospect” and the rediscovery of two “Z-caves”. The ‘Z-caves’ were previously known but unexplored due to the uncertainty of their whereabouts. Prospecting trips included the following regions:
- East of Devil’s Lair
- West of Devil’s Lair
- Boulder Jenga
- Z-Caves past Wherrets swallet
- Z-Caves via 6 Road (location of the rediscovered Z-Caves)
- Bunyips Lair area (location of Hot Prospect)
- North of JF202
Text: Fleur Loveridge
Photos: Axel Hack
Download: Summary Expedition Report