Reaching the shore of this nameless – somewhat desolate looking patch of water we skirted around its edges until we found the caves. To any caver the rock – a shattered dolostone should suggest some promise – though the fractured nature of the material might also suggest a material that is to crumbly for the formation of cave tunnels.
The ideal cave rock would be a nice thick strata of limestone. Dolostone is porus – like a sponge – and the water seeps through vugs and is not concentrated in any particular place. Limestone has a tight interlocking crystal structure and water only penetrates along joints and bedding planes. Thus tunnel formation will be concentrated along those arteries.
If you know your local geology you will know the orientation of the local joint sets – the thickness of the bedding planes and the location of impermeable shale layers above which the water is concentrated. In short cave passages are somewhat predictable and this is the specialty of cave hunters.