An AG Society-supported crew of cavers and cave divers is attempting to reach deeper into an Australian cave system than anyone has ever done before.
The Nullarbor Plain, the world’s largest limestone karst landscape, is tens of millions of years old. The Nullarbor – a dry, flat, 200,000sq.km savannah – stretches 1100km along the southern coast of Australia from Balladonia east of Norseman, WA, to north of Yalata in SA. Above ground it is famously featureless. Edward John Eyre, the first European to cross the Nullarbor in 1840–1841, described it as the “sort of place one gets into in bad dreams”. But beneath the surface is a complex world of tunnels within a vast slab of limestone. Much of southern Australia is also riddled with smaller blocks of limestone. Find the full story in the Jan/Feb issue (#130) of Australian Geographic.
Beginning 190,000 years ago, Undara Volcano in far north Queensland erupted, not with a bang but a long, seething gush of lava. Undara disgorged a colossal 23 cu.km of molten mayhem. It spread across the plains and filled ancient river valleys to the brim. Over time, the lava atop these deeper valleys cooled to form a dark, hard crust. Meanwhile, below decks, the liquid lava kept surging downstream. In essence, as it moved on, the lava fabricated its own insulated pipeline. By the time Undara was a spent force its farthest run had travelled 160km. In recent geology, no other single volcano on Earth has a longer lava flow. Visitors can see the remnants of the lava pipeline at Undara Volcanic National Park. Nearby the limestone formations of Chillagoe-Mungana Caves National Park and the distinct sandstone ravines of the region are also a delight to geology lovers.