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View Full Version : Any geologists on here? What the hell caused this??


TonyB
25th November 2006, 19:15
Very not biker related. Mind you, I guess if i were an Aussie adventure rider I'd go on an expedition to have a look. I was mucking about on Google Earth and I found something odd in Australia. Not hard I know.

This has me puzzled. In the pic below, the area you are looking at is 42km from corner to corner. It reminds me of the ridges and troughs water makes when it flows arcoss sand- if thats what this is, then a whole lot of water would have had to flow across the screen.

So what caused it? The area of the pic is 25°33'00"S 137° 0'00"E But the whole area looks to be at least 300km from end to end. There are a whole bunch of lakes to the south.
Rep for a sensible answer
Karma
25th November 2006, 19:17
My guess is that sand carried by the wind has acted like a sandblaster, and you may find that the troughs were made up of softer stone like limestone or something...
Steam
25th November 2006, 19:47
They are sand dunes which got buried and then solidified, hundreds of thousands of years ago. Oz is an OLD place.
Skyryder
25th November 2006, 20:12
My guess is that sand carried by the wind has acted like a sandblaster, and you may find that the troughs were made up of softer stone like limestone or something...

...........or something............like a bloody monster trail ride.

Skyryder
TonyB
25th November 2006, 20:23
They are sand dunes which got buried and then solidified, hundreds of thousands of years ago. Oz is an OLD place.

Really? Fark. Ta mate.
Ixion
25th November 2006, 21:05
Buried by what?
Steam
25th November 2006, 21:37
Buried by what?

That was just what I remembered off the top of my head, my wine-addled memory got it a bit wrong. They are fossilised dunes, but not actually turned to rock, just compacted over time and stopped moving, now covered in scrubby vegetation. They were never buried.
They stopped moving about 15 000 years ago when the climate changed at the end of a glaciation period. During that cold snap, the wind blew from the same direction for thousands of years. Wow!
Since then, the wind hasn't been strong enough or persistent enough to change anything. Some good examples are in the simpson desert, and they are called fossil linear dunes.

Geological time is amazingly long, and interesting things happen in it eh??
Ixion
25th November 2006, 21:58
the wind blew from the same direction for thousands of years. Wow!
,,



Sounds like Wellywood.
Hawkeye
26th November 2006, 08:28
Sounds like Wellywood.

....:rofl:
SwanTiger
26th November 2006, 08:32
Looks like the arse of an 80 year old porn star, zoomed in 100 times. Not that'd I'd know what an 80 year old porn star's arse looks like.
ninjac
26th November 2006, 09:52
I know they have a big pinapple in QLD, but I that is one farken big walnut.
ZorsT
26th November 2006, 10:49
It could have been formed during one of their 'floods'

Apparently every so often that area becomes one great big lake/river/sea, with masses of water flowing inland and flooding everything.

edit: google found this

http://www.csrl.ars.usda.gov/wewc/icar5/individuals/101.pdf
SPman
27th November 2006, 00:58
They are sand dunes which got buried and then solidified, hundreds of thousands of years ago. Oz is an OLD place.
Yeah - thats what they look like - windrift dunes.
Rocks around our neck of the woods are around 2,200 million years old !