Sunday, 29 March 2015

The Devils Marbles

The Devils Marbles in the Northern Territory of Australia is one of the most photogenic landscapes I have ever visited.


  1. Like the moon in the last two shots...
    adds to the picture.
    What is the geological story behind the shapes?

    1. Wikipedia has a good explanation of how they were formed.

    2. I would have guessed at sandstone NOT Granite!

    3. Me too. The granite is surrounded by sandstone though, so maybe it stains.

    4. Wow, that is fascinating...
      Susan, you are probably right that the sandstone stains...
      it is often iron rich... the ironstone used in the forge here looks to be remains of an iron pan...
      probably formed at the junction of the limestone and the underlying sandstone...
      but, to my mind, that wouldn't explain the entire story with these boulders...
      the stain is very shallow on the split one... but others have deep layers...
      it could be that windblown, iron rich sandstone particles continue the staining long after the chunks of granite are above ground... percolating rust into the cracks formed by the 24hr freeze/thaw cycle.
      What would confirm that is a difference in colour where flake off has occured...
      rather like plane tree bark.

  2. Near Salton City, in Southern California, there is something somewhat similar called the pumpkin patch.