We end our visit to the quarry, and our geology excursion, looking over the quarry and the bush behind. Who knew that such geological wonders was at our doorstep!
Tag Archives: kulnura
Volcanoes and All That – Part 5
We also found different minerals in all different shapes and sizes.
The minerals here formed inside a cooling rock, and looks like an egg.
These minerals have formed between two layers of bedding.
But the most fascinating was this specimen, which looks like a miniature garden of crystal.
Volcanoes and All That – Part 4
There was a variety of heavy machinery at the quarry. Some were in every day use.
But there were some older machinery in the less used corners of the mine which reflects the quarry’s 50 years of use. I found these more interesting.
Volcanoes and All That – Part 3
When the rock is blasted it forms nice columns, like these. The Giants Causeway in Northern Ireland have similar basalt columns, but in a seaside setting.
They are surprisingly heavy for their size, and are really hard rocks. These are crushed and used to make super concrete. This is the concrete for really big structures, like the World Square building and Anzac Bridge in Sydney.
We were allowed to take some home, and our columns sit happily in our garden at home.
Volcanoes and All That – Part 2
Looking at the walls of the quarry up close, you notice that the grooves lean this way and that, like someone has sketched it.
The grooves are formed when magma, coming out of the volcano, cools. Hubby the geologist says that the way the grooves lean point to the coolest point. Since the grooves on each layer point in different directions, it tells you that the volcano was active many, many times.
Close up, it looks very beautiful, like artwork.
The kids were pretty enthralled too.
Volcanoes and all that – Part 1
Looking at the landscape around Sydney now, it’s hard to believe that at one stage the area harboured some active volcanoes. The evidence may be hard to find now, but they are there.
Back to the geology excursion, the second half was a visit to Kulnura Quarry, in the tablelands of the Central Coast. The quarry produces basalt to be used in concrete and road base, and basalt (recalling all those high school science lessons) comes from volcanoes.
We could drive into the quarry. Here we are at the top of the hill.
We drive 160 metres down to the floor of the quarry.
And look back up to where we started.
That’s 50 years worth of digging – and they still haven’t hit the bottom. The manager said that there’s another 50 years’ worth of basalt underneath.
Static and Silence 