Undara's underworld

Undara’s underworld Townsville Bulletin, 1998 “Welcome to the bat cave,” whispers our guide Jimmy Richards, or JR as he prefers to be called. In cool darkness, twenty-five metres beneath a parched outback savannah plain, the click of a powerful spotlight illuminates an arched basalt ceiling, and we see hundreds of small black creatures wriggling over the urea-stained rock. “One time when I first explored this tunnel,” says JR, “my torch died and I spent three hours stumbling over rocks, scraping and bruising nearly every part of my body before I found my way back to the entrance.” I’m not surprised. As we reluctantly agree to turn our torches off for the same effect, deep inside the bowels of Barkers Tube, it becomes vertiginously black. Even after my pupils dilate, I can’t see even a faint silhouette of JR, or anyone else standing by me. I just hear some nervous, shallow breathing. Deep below the flat, sunbaked plain of Australia’s Gulf savannah is an underworld of horseshoe bats, white cockroaches and blind slaters. Their home is shared by an array of nocturnal insects in what many scientists claim to be a biological treasure trove of new species. Like an underground railway tunnel to, nowhere really, just down, we follow the lava cave’s gradual decent as JR tells how he first explored the cave system as a boy. “As ringers, we used to come down here to get out of the summer heat, but no one bothered to go too deep. Once I crawled to the end of this tube and came out through a broken hole, face to face with a python,’ he laughed. The cool, dark tunnel echoes with our shuffling footsteps and the faint sounds of bats squeaking above. The ancient lava tubes, now a popular destination for outback visitors, easily disguise the forces of their creation that once shook the land. Let’s go back in time for effect. One hundred and ninety thousand years ago when the earth trembled in north Queensland and Undara awoke, spewing volcanic clouds of ash into the sky and bathing the land in a fiery glow.

Wave after wave of molten lava poured from its crater and rolled slowly across the flat surrounding plain - more like milk boiling from a saucepan than a pyrotechnic explosion incinerating everything in its path. Gas bubbles rose through the 1200 degree Celsius lava and burst on the surface, spraying up fire fountains and tainting the air with chlorine and hydrogen sulphide. In several weeks the lava blanketed 1550 square kilometres. The lava flowed mostly to the north and west, channelled in part by dry river beds. As they cooled, the rivers of molten rock formed an outer crust, creating tunnels that kept the faster moving viscous magma flowing over the sloping plain. Like a river, the lava tubes snaked across the landscape, pooling and cascading for many kilometres. As Undara’s eruption slowed, its three main molten arteries continued to drain the fiery magma from its heart until the flow stopped, solidifying at the end of the tubes, leaving black basalt tunnels hidden below the devastated landscape. One major flow, between Junction Creek and the Einasleigh River, drained for 160 kilometres to become the world’s longest known lava tube. For centuries the tubes lay undisturbed as the hard basalt and granite landscape slowly weathered and regenerated. Initially, tropical rainforest covered the region. Then grassy woodlands replaced the rainforest as the climate gradually became drier. In recent centuries, some narrower sections of the tubes ceiling, close to the surface, collapsed to form moisture-laden depressions and vine thickets. Today, as road trains and four wheel divers pound the Kennedy Highway and Gulf Development Road that cut across the basalt and granite plain, another wave has started. Now, tourists are discovering what scientists already know to be one of Australia’s greatest geological wonders. With help from the Collins family who established Undara Lava Lodge in 1990, and Queensland’s National Parks Service, the lava tubes are hailed as a model for conservation and sustainable use. From a handful of people who visited the tubes in the late 1980s, a tourist village now caters for 200 people a day during the peak ‘dry’ season from April to October. There is a campsite, tent village and accommodation in restored railway carriages to cater for tourist

buses and self-drive vehicles. Visitors have a choice of ‘do it yourself’ camping or can pay for the fine restaurant and carriage cabins. Educating the growing tide of visitors keen to experience Undara and other significant geological sites in the Gulf region, an enterprising group of professional guides have established Savannah Guide Stations at other geologically significant sites stretching from central north Queensland to the Northern Territory. They include Cobbolt Gorge in the upper Einasleigh region and Hell’s Gate, two hours west of Burketown. Visiting the lava caves can only be arranged with a guide and to really appreciate the legacy of Undara’s rage there’s no better or safer way. Otherwise, there’d be an awful lot of hapless people lost and wandering somewhere in the underworld.