In my lengthy Ancient History post below, I mentioned the soupy breccia that formed after the meteor impacted in the ancient ocean 350 million years ago. The last time I was down near Roundrock, I snapped this photo of some exposed breccia with the round rocks eroding from it.
The rock face here is about ten feet high, and I am standing perhaps five feet below its base. Note the sculpting of the breccia. That was done by waves in the ancient sea so very long ago. Beautiful!