(Text version)
LEGACY OF A VIOLENT PAST
By David R. Griffiths
If
you're sitting in an aircraft taking off from Melbourne's Tullamarine
Airport, you're more than likely to catch a glimpse of a deep ravine
two kilometres from the airport's western boundary.
Worn by the gentle action of water against rock, the deep gorges of the Organ Pipes National Park - which cut through what is known as the Keilor Plains - testify to a violent past.
A million years ago the area was alive with volcanoes. Smoke would have filled the air from bush-fires started by the molten rock as it poured across the landscape, creating one of the world's biggest lava flows.
Steam would have filled the air, too, as some of the volcanoes ejected scoria, a light reddish rock full of holes caused by escaping gas. As the deep basalt lava flows cooled, they contracted and formed into columns.
An exposed cliff face of them has given the park its name, because of the striking similarity to organ pipes. Less than a kilometre upstream is another rock formation, the Tessellated Pavement, which looks like a cobbled lane. A little downstream are sandstone formations thought to be 400 million years old. The park is located on the Calder Highway opposite the Calder Park Thunder-dome, Sydenham.
Panorama • March 1993Worn by the gentle action of water against rock, the deep gorges of the Organ Pipes National Park - which cut through what is known as the Keilor Plains - testify to a violent past.
A million years ago the area was alive with volcanoes. Smoke would have filled the air from bush-fires started by the molten rock as it poured across the landscape, creating one of the world's biggest lava flows.
Steam would have filled the air, too, as some of the volcanoes ejected scoria, a light reddish rock full of holes caused by escaping gas. As the deep basalt lava flows cooled, they contracted and formed into columns.
An exposed cliff face of them has given the park its name, because of the striking similarity to organ pipes. Less than a kilometre upstream is another rock formation, the Tessellated Pavement, which looks like a cobbled lane. A little downstream are sandstone formations thought to be 400 million years old. The park is located on the Calder Highway opposite the Calder Park Thunder-dome, Sydenham.
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(c) Photos and text David R. Griffiths 1993. Free for non commercial use such as school project, not to be republished print or electronic without permission.