400 million years ago Australia was still part of the content called Gondwanaland, small plants had already commenced growing on the dry land and some marine creatures had probably evolved into insects but these were early days for complex lifeforms on land. Vegetation was basic with probably nothing tree-like existing. This was also tens of millions of years before dinosaurs arose. Normally the rocks from this period would be buried deep beneath the current surface of the earth but there is an anticline, where the rock layer has been bent upwards, in the suburb of Deakin that was further expose because it was also the site of white clay mining that was used to help build Canberra.
I know nothing about geology but I am intrigued about how this planet that we live on came into being and then produced the richness of life that we all enjoy. So my interest was piqued when I read the paragraph below:
“On one side of the sports ground at Deakin shops there is a high wire fence surrounding an outcrop of rock which must puzzle many residents and passers-by. The outcrop has been preserved by the NCDC because it shows the various parts of a typical fold very clearly. The crest of the anticline is nearest to Deakin shops, and best viewed from the sports oval, although it can be seen from outside the fence. It is probably of more interest to the student than to the tourist. When the sports ground is not in use, access to the oval can be obtained from the caretaker, Mr G.F. Hearne, of 76 Newdigate Street (adjacent to the grand stand gates), phone 81 2056.”
That paragraph is out of date in its description of the environ around the anticline but it was enough to convince me to visit the location, which is only about a five minute drive from my home. I wanted to see the anticline also because it is part of the rich, natural history that makes Canberra such an interesting place to live. I have copied a paragraph below from the ACT Heritage Register to better explain the significance of the anticline:
“The Deakin Anticline is a significant element of the sedimentary rocks that comprise the Yarralumla Formation in the ACT. It is a clear illustration of a simple Anticlinal formation and a highly visible feature of the last marine incursion into the ACT region. It is also an important teaching site in that the geological features of an Anticline are clearly shown and readily accessible, particularly on the steep eastern face of the Anticline where the major Anticlinal hinge lies.”
So on Saturday afternoon, 5 September, the sun was shining making it a beautiful time to photograph at the anticline. As you can see in the map below the anticline is completely surrounded by the suburb of Deakin and there is a soccer pitch to the immediate north of the anticline.
When I arrived, I envisaged a quiet suburban park with a few families possibly enjoying the early spring weather but I was greeted by a full-on amateur grade soccer match underway on the field. People around the area probably thought that I was arriving to photograph the exciting game rather than a pile of rocks.
Leaving the carpark there was an obvious path to the equally, very obvious and rather large anticline right in front of me. The sign pictured below was a bit of safety advice but it was also a way to look after the anticline that can be damaged by too much wear and tear.
The first information sign about the anticline
A few steps on, almost at the base of the anticline was a sign that explained more about the site. I started my visit by heading northwards, to the right of the sign. I was admiring the overall view of the anticline but I was also trying to pick out patterns in the rock that would make for interesting photographs.
A sign with more detail about the history and how to view the anticline
Maybe the light was too harsh or maybe the noise of the soccer match was disturbing me but it was hard to find the patterns that I was after. I did find two that I thought were interesting. The first one was the rocks jutting out from the anticline, probably showing the stratification, or layerings in the rock. The second shot shows possibly a different view of stratification, instead of cutting into the layers it is actually looking down on the layers. In the bottom left of the picture you can see uneven wear on the rocks that has exposed the tops of different layers, hence the colour variations.
Exposed rock edges showing the stratification in the anticline
(Canon EOS 6D Mk II with a Canon EF100mm f/2.8L Macro IS USM [ISO 100, 100mm, f/11 and 1/125 SEC])
Wavey rock patterns
(Canon EOS 6D Mk II with a Canon EF100mm f/2.8L Macro IS USM [ISO 100, 100mm, f/11 and 1/50 SEC])
I continued walking anti-clockwise around the anticline. I noticed how the western side showed the layers as well but there were plants growing in front of the rock and on the top.
Looking along part of the anticline as the track cuts between the two halves
(Canon EOS 6D Mk II with a Canon EF100mm f/2.8L Macro IS USM [ISO 100, 100mm, f/11 and 1/50 SEC])
Following the trail as it bisected the anitcline I walked onto the eastern half. There was an area of exposed rock that had multiple lines running through it seeming to intersect at 90 degrees with other lines. I wondered if these cracks had been made by the pressure applied to the anticline when it was initially bent by the strong forces applied to it.
Rock patterns on top of the anticline
(Canon EOS 6D Mk II with a Canon EF100mm f/2.8L Macro IS USM [ISO 100, 100mm, f/11 and 1/50 SEC])
Also on top of the anticline there was an interesting rock that almost had a smooth surface texture. There were still cracks in the rock but it almost appeared smooth. However, that was just on the top with the side away from me being the harsh, dull surface of the surrounding rocks. I am not sure what caused this smoothness because none of the other rocks had a similar appearance. I wondered if the smoothness was the result of many people climbing on it, but the consistency across the whole rock, even in areas where people would not climb seemed to discount human action as the cause of the smoothness. The most likely cause was weathering. In talking about the weather you will see how the clouds in the background show that the weather was changing that day, although the clouds did clear again shortly afterwards.
An interesting rock on the top of the anticline
(Canon EOS 6D Mk II with a Canon EF100mm f/2.8L Macro IS USM [ISO 100, 100mm, f/10 and 1/100 SEC])
Even though I was there to photograph rocks I did not miss an opportunity to photograph a Purple Coral Pea (Hardenbergia violacea) with its brilliant purple flowers. This particular plant was under a tree on the south-west slope. It was just getting enough light for photographing but the wind had picked up a little causing it to move continuously. Even though this was an Australian native plant I suspect this small bush had been planted, possibly by a resident of the neighbouring retirement village, to add some colour to the small park.
Purple Coral Pea
(Canon EOS 6D Mk II with a Canon EF100mm f/2.8L Macro IS USM [ISO 500, 100mm, f/9.0 and 1/100 SEC] 2 photos focus-stacked)
Following the path back around to the eastern side of the anticline there were three Cabbage White Butterflies (Pieris rapae) fluttering about. They met in mid-air, where they would haphazardly circle each other before breaking contact and flying in different directions. I assumed that they were looking for mates. The one in the photograph landed on the ground among some low plants. It did not seem to mind me getting close. I had to lie down to get an angle under the vegetation. Just at that time I was photographing, a man and a women walked past. I heard the unnatural break in the conversation as they saw me, a grown man, lying face down on the grass, with a backpack, apparently photographing a boring plant. Oh well, I was happy.
Cabbage White Butterfly on the ground
(Canon EOS 6D Mk II with a Canon EF100mm f/2.8L Macro IS USM [ISO 160, 100mm, f/9.0 and 1/200 SEC])
This side of the anticline was the best for seeing the layers of the rock. By this stage the sky had cleared so I thought that the reddish rock contrasted nicely with the blue sky. I also found another rock pattern to photograph.
Northward facing edge of the anticline
(Canon EOS 6D Mk II with a Canon EF100mm f/2.8L Macro IS USM [ISO 100, 100mm, f/13 and 1/100 SEC] three shot vertical panorama)
Detail of the rock pattern, almost with a golden-yellow colour
(Canon EOS 6D Mk II with a Canon EF100mm f/2.8L Macro IS USM [ISO 100, 100mm, f/9.0 and 1/100 SEC])
It did not take long to walk around the anticline and it was a little strange trying to photograph nature in what was a built-up area. That said, I am glad that I saw this structure. I was interested to see this example of the earth’s prehistory sitting in an urban park of Canberra and it was nice to lose myself in photography for an hour on a Saturday afternoon.
Thanks for reading this post and thanks also for looking at my photos. I hope you come back again to read more about some of the wonderful natural things that the Australian Capital Territory has on offer. All the best until the next post.