Pond Boss Forums GENERAL QUESTIONS Water chemistry White ring on clay bank

On my new 1/4 acre pond that is just filling, there is a white ring about three feet up the bank from the water, and maybe 8 to 10 vertical inches above the water. The ring is at the upper line of the wet clay that is absorbing water that is wicking up the banks on the dam. The ring is about six to ten inches wide. What could this be? The pond is in all red and gray clays.

Here's a picture.