Sunday 21 February 2021. Today, a cool day towards the end of what has been a cool summer, we visited the small but perfect Organ Pipes National Park for the first time in ten or so years. The closest national park to central Melbourne lies on the edge of Victoria’s Western Volcanic Plain, which stretches from Melbourne’s western suburbs to close to the South Australian border and is the third largest volcanic plain in the world.
The park lies within a horseshoe bend of Jacksons Creek, whose flow over millennia has gouged an impressive valley out of the volcanic plain. The carpark and main picnic area lie on an eroded volcano above the valley. The park’s interesting geological features – the eponymous Organ Pipes, as well as the Rosette Rock and the Tessellated Pavement – are located along the creek within the valley; a single asphalt path leads down to them.
After a pleasant picnic in the somewhat cramped main picnic area we descended into the valley along the asphalt path. As we did so we were afforded striking views of the folds of the valley’s sides.
At the bottom of the path we arrived at a smaller picnic area, just beyond which lie the Organ Pipes, so called due to their resemblance to – well, organ pipes. The pipes were formed around one million years when lava from Mt. Holden and other volcanoes filled depressions in the landscape, cooled and hardened into basalt, then cracked. Over the millennia Jacksons Creek has worn away the basalt and exposed the columns. The famous Giant’s Causeway in Northern Ireland is another example of a columnar basalt structure.
After admiring the pipes for a short while, we followed the asphalt path alongside Jacksons Creek to Rosette Rock (whose name always makes me think of the Rosetta Stone in the British Museum, an altogether different artefact), an outcrop of columnar basalt, the front of which is shaped something like a wheel. It is quite curious but only momentarily diverting. We did spot a wallaby sitting a short way off. See if you can find it in the photograph!
Further along the path we came to the final feature of the park, the Tessellated Pavement, again an arrangement of basalt columns but in this case with only their tops showing, having been worn down by Jacksons Creek. Comparisons with the Giant’s Causeway are justifiable, though of course the Tessellated Pavement is not nearly so spectacular.
We had now come to the end of our visit, but instead of returning along the asphalt path some 700 metres to the Organ Pipes, then ascending the hill out of the valley – as we should have – we walked past the Tessellated Pavement and into the long yellow grass beyond. I had thought I could discern a promising if narrow path through the grass, which might have taken us up to the carpark via a ‘back’ way, but alas, it ended only in a wire fence!