I love maps. I can stare at them for hours, particularly when I’m planning to go somewhere new. Before the almighty internet these maps consisted of road map atlases and specially printed large sheet maps for travelling. I like hunting down all the little barely noted places on the maps – usually natural interest spots like mountains, lakes, volcanoes, oddities and lots of interesting things off the beaten track. Nowadays I can get lost in Google Maps never to be seen again.
I can’t remember which year it was, but it would have been in the second half of the eighties, my family headed down to the south-east of South Australia. I hadn’t been there since I was five years old, so it was a much anticipated trip. So out came the maps and I hunted for all the places I could visit.
The south east of South Australia is called the Limestone Coast. Mostly because that is what it is made of. It has a fascinating geological history. If you look at the satellite image, you can see a series of lines on the land parallel to the coast – these are ancient coastlines as the area has be inundated multiple times in fairly recent history. The limestone itself was deposited around 38 – 15 million years ago (Miocene). To add even more interest approximately 4500 – 6000 years ago (I can’t get a solid number on that), Australia’s youngest volcano blasted through that limestone to form Mount Gambier. The Indigenous people of the area have the event recorded in their histories. The volcano was formed by a hotspot coming into contact with groundwater. This equals a very large bang and the resultant maar complex (after multiple eruptions) is quite extensive – and now filled with water.
One of the craters (if you zoom in on Mount Gambier in the Google Map above – or scoll down, I added another map) is called the Blue Lake and is famous for turning an electric blue ever summer. It has something to do with bacteria or light refraction or whatever the latest findings are (it seems to change all the time), and it is quite a beautiful sight.
The reason it is filled with water is because of the limestone. There is a lot of water under the ground in the south east. There used to be more – in the early 1900s the vast swamps of the south east were drained for farmland and to enable people to travel down there (there used to be floods apparently, restricting population movement). The drains are still there and I find them somewhat depressing as this would have been a wonderful wetland area before we interfered. But I can understand why it was done ::sigh::
This is where I waffle on about human impact on the area, but I don’t want to depress you. One thing I do want to point out – here is a painting of Mount Gambier from 1864 by Eugen Von Guerard
, a well known colonial painter (from the west at the top of Mount Gambier). If you visit the National Library Australia link and zoom in, in the background you can see that the land was swamped with water.
And here is a photo from recent times of Valley Lake and Brownes Lake (from the east facing the peak of Mount Gambier). In the painting Browne’s Lake is in the foreground. In the photo, it is in the background and non-existent. Valley Lake is the only water in the crater.
Or Google Maps will give us a better view.
In summary, the water table has dropped due to a combination of draining the land and using the water (Blue Lake is the source of all public water in Mount Gambier).
And this is where I return to my story after waffling all over the place (I can’t help myself, the place is fascinating). The maps – I stared at those maps as a young teenager and came across a little symbol off the beaten track declaring the location of The Little Blue Lake.
Most people know about the Blue Lake – that’s the big one in the crater above. But what is the Little Blue Lake?
And that little spot on the map – The Little Blue Lake – is a sinkhole filled with water. We went and visited it back then and it truly was a little version of the Blue Lake complete with the sapphire blue water.
Almost every time I’ve been to the South east, I have visited this little lake. It was a popular swimming hole (in the literal sense) and a cave diving site (cave diving info and a map of the lake
) and for me it was a reminder of what can be found when looking at maps – it certainly wasn’t in the tourist brochure at the time.
This is a photo from 2006. Here it is a little greener than blue, and having done a little research online for this post, apparently it no longer turns blue 🙁 Pollution – it is full of rubbish at the bottom and is surrounded by farmland. So I initially set out in this post to rave about this little favourite spot of mine, only to discover that it has literally been destroyed. It is still there, it is still a sinkhole and a diving site, but although I previously wouldn’t swim in it because it is too deep, now I’d fear what I might catch if I went swimming. I’m sitting here, thoroughly grateful for convincing my father to take us to see the Little Blue Lake back in the eighties, so I can now remember that it was blue, just like the Big Blue Lake. If you want to be truly horrified, check out this article from three years after the above photo
. At least it has one photo of it blue – I don’t have one as it was before digital cameras. I guess my kids won’t get to see it blue 🙁
The Limestone Coast is still a fascinating place, despite human impact and I’m sorry this ended up being a completely different post from what I had intended. We still like to go there – Mount Gambier is over 500kms from where we live so it is quite a hike, but it is also an alternate route to Melbourne, so we get there from time to time. I will probably rave about this area again as there is a lot of stuff to see down there 😀
And this is my submission this week for Our World Tuesday
– don’t forget to drop by and discover all the corners of our wonderful planet.
But for the moment, I’m signing off and going to go pick up my new camera 😀