9 June 2017

Friday fold – or is it a fauxld?

Posted by Callan Bentley

Check this out: is it a fold?

Annotated to show the 3D expression of the ‘bed’ (left) and cross-sectional view (right):

Here’s a 3D model of the outcrop to better convey its shape:

This is in the same sandstone unit I blogged about on Tuesday with the apparent soft-sediment deformation. This could be another example of the same general class of pre-lithification structures, or it could be an optical illusion. Again it’s hard for me to make the call since the folded “layer” is the same composition as the layers above and below, yet if folded, it shows a significant rheological contrast. I don’t get it.