11 January 2012

Splotchy Liesgang banding

Posted by Callan Bentley

At the Three Rondavels overlook in the northern Drakensburg Mountains of South Africa, I saw this chunk of quartzite with a peculiar variety of Liesegang banding (iron oxide staining of the rock by groundwater):

A short distance away, I found another example:

In one key way, I liked this second example better, even though the Liesegang banding wasn’t as well expressed here. The improvement is that it also shows bedding, while the first sample was more massive. You can see that the Liesegang stain fronts overprint the original sedimentary layering within the quartz sandstone:

It’s a palimpsest of geological process!