The fact that Iron causes the redness in the rock is obvious. The question that I have is whether it is Ferrous or Ferric that is present.
When I was a freshman in high school I took a correspondence geology course at the local community college. The program worked like this: you check out a series of video tapes, take a test then repeat. I watched five minutes of the first video and found it too boring. So I just went in and took the test. Every two weeks or so I would go in and take a test. No videos, no reading, nothing occurred in between. I got a B+ in the course, the problem is that I didn't learn a thing (shocking I know). I am now really kicking myself . If only I had applied myself then I could be spewing all kinds of useless info onto Ainsley's defenseless little ears right now.