This circular feature is natural and locals have various theories on its formation. Some imagine it to be a shallow crater of volcanic origin, and some noting that there are a number of them in the area, and that they have a crescent ridge on one side thought they may be meteor craters with the meteor having hit at an angle thus creating a ridge on one side. It of neither origin, but is a deflation hollow. Deflation hollows are hollows created by wind erosion on clay plains. The hollow will on occasions retain surface water. While holding the water, wind creates ripples which then shape the shore line, even as water levels slowly recede. If the wind is variable in direction the hollow will tend to be almost perfectly circular. If the wind prevails from one direction as in Wimmera of Victoria, the hollow and ephemeral lake will be more elongate, the long axis across the direction of the wind. Even in variable wind direction regimes, the dominant wind direction will create a crescentic dune on the leeside of the hollow when it is dry. Such a dune may be stabilised by vegetation and sustained by the periods of dry when the bed may be deflated further.
This particular deflation hollow displays the crescent dune on the NE side, and at the time that the image was taken, the hollow was water-logged and the grass within green as there had been recent heavy rain, after a severe and lengthy drought.
Thank you for this explanation Ian.
This deflation hollow is located on South Muthong Station, a grazing property on the inland plains of southern Queensland, Australia. I have just had 2 weeks vacation staying with family in the area. As it is so far from the sea or the mountains, some people imagine it is boring landscape with little to do. For the residents there is much to do, and for the holiday maker there are boundless possibilities. I went flying, water skiing, bike riding, quad bike riding, fishing, canoeing down the Balonne River, wildlife photography (prolific birdlife, kangaroos, wallabies, giant cicadas, emus), swimming, knee-boarding and jet-skiing on the river, sunset cruising on a barbecue barge, farm visiting, shopping, grape picking, watching a rockmelon harvest, visited the Surat art gallery and excellent historical museum, worshipped, played backyard cricket, celebrated Christmas and New Year with family, read a few chapters though there wasn't time for whole books, had many stimulating conversations with amazing people, shopped, bathed at 40C in thermal public baths and could have done much more. The list of possibilities goes on. Anyone need a travel consultant?
I like your collection (Welcome to my favs!) especially the tag geomorphology and your explanations (Of course as geologist!).
With my best wishes and greeting from Berlin - Alex
Thanks Alex. I am just as pleased to find someone who appreciates the "geomorphology" tag! I have had
only one visit to Berlin, a brief one, but loved the whole experience. I guess you have seen the few images of Berlin in my galley too.
Thank you so much for the Favourites listing. As soon as I can I will enjoy your gallery. I have just this moment arrived back home from Tonga, and have much catching up to do and some uploading as well. It is all coral in the parts of Tonga where I was, though the uplifted islands have plenty of caves and gorges for amusement.
Best wishes from Sydney,
Hi Ian, I also appreciate your scientific eye and explanations - I'm a science teacher and I gather you are a geologist?. Found your photos on google earth while looking around at the landscapes that are experiencing floods in Qld. Will be taking a closer look in the future.
Any suggestion that I am a geologist is a bit wide of the mark, for that science is not one that I have studies formerly. But geomorphology is an earth science that I have enjoyed professionally, as an educator, and recreationally.
Glad to make your e-acquaintance.
And I am pleased that you valued the descriptions as well as the images.
Regards from Brisbane,
Hi Ian, You have an interesting set of photos that I have started to look at. OK....geomorphology it is, and so you should find the pics of the high country interesting also. It is my favourite place to hike but I also trek there with students as a school related activity.
No doubt there will be some "geomorphing" that you recognise!
Greg in Newcastle.
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Photo taken in Dirranbandi QLD 4486, Australia
Misplaced? Suggest new location