Let’s talk about Bluestone.
Sawn random basalt steppers and format paving.
Torquay, Victoria
It’s a term thrown around pretty widely in stonemasonry, especially here in Victoria, Australia. Rightly so. Bluestone isn’t stone, per say. Its use in masonry nomenclature is as a cultural term to encompass dolerites (Tasmania) and basalts (Victoria).
So, let’s talk about basalt.
Victoria is home to the third largest volcanic plain in the entire world, the Newer Volcanic Province, or the Western Victorian Volcanic Plains. It roughly runs from Craigieburn in the east, to Portland in the west, and from Colac in the south, across to its northern edges at Clunes. The area makes up about 10% of the state’s land area and encompasses some 2.3million hectares.
Newer Volcanic Province (source romseyaustralia)
The plains began to form around 6 million years ago when Victoria was home to more than 400 active volcanoes. When you consider that basalts are the result of molten lava and magma cooling more or less at the surface of the earth, building a home in the burbs back then might’ve been a bit trickier than it is today!
It is thought that the plains remained active as recently as 7000 years ago, and some geologists suppose that the plains may not actually be inactive, rather in a dormant state and may become active again soon. Records show that newer volcanoes in the area have erupted every 2000 years or so for the past 40,000 years, and considering there hasn’t been a major eruption for past 5000 years, a “significant eruption seems well overdue”
Across the far west of the state, in the area now encompassing Warnambool, Port Fairy and Portland, the Aboriginal people, the Gunditjmara are thought to have the oldest orally passed down story in history still being told today. It centres around the Budj Bim volcano which erupted around 37,000 years ago.
‘Long ago, four giant beings arrived. Three strode out, but one crouched in place. His body formed a volcano called Budj Bim, and his teeth became the lava the volcano spat out’. Imagine witnessing a landscape you know so well being so drastically shifted, reset with fire and stone.
From the lakes and waterways formed from lava flows after the ancient eruption of Budj Bim (also known as Mt. Eccles), the Gunditjmara developed aquaculture systems, working with these new (new in the sense that they were only about 30,000 years old at the time) basalt formations and manipulating kilometres of land to trap and fish eels in weirs and damn. One of these systems that included basalt dam walls has been dated to over 6,500 years old. This is, to my knowledge, the earliest use of ‘bluestone’ in Victoria, if not Australia in farming.
As we can see from looking to our geological past, from times as recent as the oldest known human story, to distant epochs far, far before any genus of Homo wandered the earth, we cannot understate the importance of the ground on which we walk today.
So why write all of this? Why spend the time compiling information about the formation of stone, its local early uses and volcanos? Because I feel that it’s important to think holistically about with what we build. To appreciate the enormous journey each stone goes through before it finds its place in your building, by the hand of a mason.
I think that there’s many interweaving aspects of the craft that makes stonemasonry special, and I hope that you, reading this and the other ramblings you’ll find here, can find something special about a profession that for me, fast became a passion.
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**References and further reading
http://romseyaustralia.com/volcmap.html
http://www.17thagc.gsa.org.au/
https://www.sciencemag.org/news/2020/02/aboriginal-tale-ancient-volcano-oldest-story-ever-told
http://www.environment.gov.au/heritage/places/national/budj-bim
