Now here is something completly different! And quite unique!
Caves don’t necessarily need to be in limestone. We are blessed in Victoria to have caves set in Limestone, Granite and Basalt (Volcanic)!! The Western part of Victoria is one of the largest Basalt plains in the world. These lava tubes are quite rare compared to Limestone and visiting cavers should definitely have a look!
Mt Hamilton Cave
This is a complex cave on a number of vertical levels extending over one kilometre. This is probably the best volcanic cave in Victoria in terms of its length and complexity. The cave actually feels (and even smells) like a limestone cave and there are a few hours’ worth of exploration possible to see the whole thing. All easy and totally suitable for beginners.
Some interesting features including the beehive chamber that is a perfect dome with hive like indentations in the walls. Until relatively recently the Mt. Hamilton lava tubes described above were the longest in Australia, but longer tubes have been found in Queensland.
This cave is very close to Melbourne but is not done often as it is on private property. The cave is a classic example of a lava tube. The cave is quite long, listed in the Karst Index as being about 300m in length. The landowner is generally friendly to cavers but permission must be sought. As a day trip I would recommend Parwan over the granite caves mentioned above.
The main three Volcanic Basalt Karst Areas are:
Mt Eccles Caves, Mt Napier Caves and Byaduk Caves
These areas are not frequently visited by Victorian Cavers (though perhaps they should be). There is scope in these areas for new caves to be found. All together there would be over 100 caves within these three main areas, and there are also campgrounds nearby which make a good home base. Bring a ladder and belay device/rope as some of the caves have partial vertical drops, normally at the entrance.
They eat your light and your clothes! Volcanic caves are peculiar compared to Limestone caves in several ways worth noting. Firstly, they are really sharp. Cotton Overalls will only last one weekend in this environment – they get shredded to bits. I would not suggest wearing an expensive cave suit into these caves as they even destroy tough fabrics such as Cordura.
Also, Volcanic Caves eat up your light. Due to the colour of the rock (often black) your torch light Is absorbed and will seem less bright. There are types of decoration specific to Basalt caves, including stalactite type formations and sometimes crystals.
Quite a few of the volcanic caves are immense and could park jumbo jets, but don’t go far or even really have a dark zone. But the size is still impressive. We take our lava caves a bit for granted in Victoria which is a shame as geologically they are nowhere near as common as limestone caves.
If you are a visiting caver i would recommend you traverse the state from West to East – Start by doing DD4 (Jones Ridge Cave), then go to the volcanic areas for a day or two, then through Melbourne, and on to Buchan in the east. That would be an epic trip.