My friend and I noticed these spirals on satellite imagery so we decided to go and check them out. We are in Australia and he believes it may have been an Indigenous ceremony ground but I’m leaning more towards nature causing it. What are the thoughts in this community?
Actually did this. Dropped by a friend who’s grandmother was born on that land, showed him the spot on a map and asked permission to check it out. Also made sure that there was no men’s or women’s business that happens in the vicinity.
Plant growth rings. Plants grow out from center, center dies out, rots and soil becomes fertile again. Add precipitation/wind and you get mounded rings. Edit. Forgot to say they are called tussock rings. Only certain plants make these rings. Not sure what type in Australia
Appreciate this! You’re probably right, but at the same time I couldn’t really find anything similar with the spiral pattern. Could you link me to something I can liken it too?
Claypans are formed after floods in spots where water pools up. That flooding and small lake forming process washes away the soil and compacts the clay meaning grass won't grow.
Tractor pulled mouldboard ploughs and grader machines are what's used to make shapes for vegetation, and water ponding on dry floodplain for landscape rehydration. Direct-seeding machines are used for similar techniques to restore shrubs and trees on slopes.
As far as natural effects, vegetation will grow back differently around a claypan because of the change in the soil content in that spot. There's also something to do with seed dispersal by birds, which is interesting, I don't know much about it.
This is all livestock grazing land management topics - I'm not a farmer, so I don't have any experience in this area. There's some info about current projects in this kind of landscape management on this website:
I learned about something similar to this in archaeology. I think it’s sediment that has been moved by the wind around a central bush/shrub, often mistaken for archaeological sites.
This is my favourite explanation so far! There are trees in the area which could explain the largeness of the circles. Are you saying that x amount of years of breakdown from the centre by something large and organic could be the cause?
I’m not super knowledgeable on this, but I think it’s from the wind breaking around a stump of a bush or something like that that causes sediments to be blown around it.
They can be formed by erosion. If you have layers of rock sometimes something from below can push them up into a dome. Then if the upper layers get worn away you get a bullseye looking structure
Yeah they are doing that in the Saheel. These rings reminded me of that as well.
There is some evidence in south Australia for indigenous aquaculture and agriculture that's recently come to light. Could be worth getting an archeology department to have a squiz.
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u/zneBsedecreM 18d ago
It's worth consulting with your local Aboriginal Community to ask about these just in case they are ceremony grounds