Undara Day 2, Lava Tubes

---

Today we took the Volcanic Valley Tour, a half-day trip around a number of lava tube sites. It started at 08:00 so we had an early bush breakfast with everything. The tour guide told us about the geology and geography of the landscape in the national park and surrounding areas. It turns out that the east coast of Australia is a long fault line that runs from Victoria in the south along the Great Dividing Range up to north Queensland where we are now. This part was stretched and then pushed together many tenths of million of years ago. Some eight to nine million years ago the same part got pressed together to form the mountain range and this sparked volcanic activity in many places. One of the latest volcano’s to erupt was Undara, some 200,000 years ago. Its crater is on top of the mountain range and is therefore not very conspicuous but the lava flows were very large and the flow goes on for about 160km to the west. This has shaped de geography in the national park such that part is basalt, lava stone, and part is granite islands sticking up. If you know what to look for you can clearly see the frozen lava waves in the landscape. Most of the vegetation is woodland savannah with small patches of remnant rainforest where the basalt is exposed. Where the main flows of lava were there are still so-called lava tubes present. These are cave tunnels in which the lava flowed but that are now empty. Some of them are accessible and the tour took us to a few. They are fascinating places where geology and biology meet. On the inside you can see the calcium and iron stains together with small stalactites and root systems from plants above. There are also animal bones in many of them as wounded and sick animals often take refuge in the caves. Only one cave has shown some traces of human activity but only of occasional use. This is probably due the facts that this area was scarcely populated by the aboriginal peoples and that at least some of them believed that unusual geological features such as caves were associated with bad spirits.



After lunch we went for another self guided walk, the Bush Walk track. It took us through the typical woodland savannah landscape and we saw several kangaroos and wallabies as well as many different birds, including six large black parrots.



After some discussion with the very friendly but slightly confused reception staff we managed to pay our bills for the stay so that we can leave early tomorrow. We aim at being in Cairns before lunch so that we can enjoy the warm costal climate a little before heading home.

---