Ventifacts - sculpted by the wind

to Earth Science Australia...

to Time and Space Science...

Ventifacts - sculptured by the wind - a ventifact tells its story

My Story - my life as a ventifact
I'm a ventifact, that is a rock sculpted and shaped by the wind. I was found in the deserts of Central Australia.
Of course the wind blows lots of sand and dust that over a long period of time creates flat and curved surfaces on me.
See me in the image below...

ventifact

In order for a ventifact like me to be created you need a place with a fairly hard surface and a wind that blows sand and dust from the same direction for most of the year...

ventifact formation

What you see is not always what you get!
What you see on the outside is not always what you find on the inside for example all the ventifacts below are from eastern Iran.
All are the same rock on the inside but have different colours and textures on the outside.
The external colours are caused by "Desert Varnish" which results when the fresh sandblasted surface of the rock chemically reacts with minerals in the blowing dust...

Desert Varnish


What do the shapes mean?
ventifact faces

Wearing away to sand...
As the rock wears away over long periods of time it becomes unbalanced and is tipped or blown over and becomes a smaller elongated core...finally becoming just a bit more of the blowing sand...
worn away core