Volcanic eruptions in Murrindindi Shire

DOCTOR Bill Birch, Curator Emeritus, Geosciences at Museums Victoria, provided information on the Cerberean Complex, also known as the Marysville volcano, even though “it’s not really a volcano in the traditional sense.”

In terms of the location, Dr Birch said, “It’s all the high country to the east of Marysville, what I call the Cerberean Ranges, but it includes some Mount Torbreck, the Royston Range, the Cathedral Range.

The Cathedral Range is sort of associated, but it’s not part of the volcanics. It’s an interesting story. The volcanic rocks are responsible for the high country, the forested country, that part of the Central Highlands, south of Eildon, east of Marysville and across to the east.

It’s a bit hard to put a town on the east because well, there isn’t one. All that high country is volcanic rock.

“It’s a complicated history, but essentially what happened was back in the Devonian about 365 million years ago, Victoria was part of Gondwana.

The countryside then would have been sort of sedimentary rocks with ranges, streams, rivers, lakes, etcetera. A bit of vegetation and not much in the way of life, but possibly some. There certainly would have been fish around about.

“All of a sudden there were some volcanic eruptions in that area. They were what we call ‘ash flow’ eruptions. You can see ash flow eruptions these days in Japan and in New Zealand, I think, but these were quite big. Then there was a series of different volcanoes erupted, different types of lava and they built up, and there were intervals in between, there probably might have been tens of thousands or millions of years in between some of these eruptions, even to the extent that lakes formed and fish were found in those lakes.

It’s actually a horizon of sedimentary rocks or lake rocks in the volcanic sequence in this first part,” Dr Birch said.

“Then, all of a sudden, a giant block of the Earth’s crust, like a big cylinder 27 kilometres across, it started to collapse. It fell into a magma chamber below. We’re not quite sure how deep, but probably 10 to 15 kilometres deep and these massive volcanic eruptions occurred…

Image by Google Earth – The Cerberean Complex was a series of eruptions around 365 million years ago.