Lots and Lots of Gold

A part of the quartz reef (the white stripe from the top left to the bottom right)

A view of one of the horizontal tunnels in the mine

Today, we drove inland a little to visit a decommissioned gold mine in a town called Walhalla, slightly east of Melbourne.  The Australian gold rush happened in the 1860s when some prospectors found large amounts of alluvial gold in streams and rivers running through the area, which wasn't populated yet.  Alluvial gold is made up of gold atoms, but instead of being in the form of nuggets, it is found as flakes.  The prospectors knew that there had to be a quartz reef nearby because of all the gold.  (Alluvial gold is often connected to the presence of a quartz reef.  Through cracks in the lithosphere, molten iron and a little bit of molten gold seep up from the mantle.  Through the movement of tectonic plates, the iron and gold get pushed closer to Earth's surface.  At the same time, water with a high silica content from the crust seeps down those cracks.  Over time, the silica crystallizes to form quartz around the existing iron and gold.  When miners are looking for a quartz reef, they are looking for "dirty quartz", which looks dirty because of the iron and gold.  If a miner comes across "clean quartz", they know there is no gold in it because there are no iron deposits in it.)  Somebody found the tip of the quartz reef sticking out of a mountain, and pretty soon, the Hercules Mining Company started mining and after years of digging, found the reef.  However, unbeknownst to them, after they found the reef, they began digging in a direction where there was very little gold.  They weren't finding enough gold and hence making enough money to continue digging, and the mine was bought by the Long Tunnel Extended mining company.  They started digging in the opposite direction, and found so much gold that the mine became one of Victoria's richest gold mine, unearthing about 13 metric tons of gold.  (The town of Walhalla grew to about 4,000 people.  Walhalla was the second town in Victoria to get electricity, because they had enough power from the mine's boilers.)  The mine required three huge boilers to produce enough power to run the mining hammers and the water pumps.  Water pumps were needed because the mine extended almost a kilometer down into the earth, way below the water table.  When the mine shut down in around 1910, it wasn't because they weren't finding enough gold, it was because it was too expensive to import wood for the boilers (coal didn't burn hot enough).  All trees within a 13 kilometer radius of Walhalla had been cut down.  Because the mining stopped, the town's residents moved away, and Walhalla lost it's electricity.  The town today has less then 15 residents, and in 1998 was the last town in Victoria (and the second) to receive power.
We will be spending the night in a caravan park just north of Melbourne, and continue on an inland rout to Sydney, stopping in the Australian capital, Canberra.