The Great Wall - stage 5

Painted the mid ground mesa today. All the mesas and buttes in this area have quite a distinctive feature to them, it looks like Nature has taken a giant sander and neatly sanded away the whole side of the mesa or it looks like something huge and green has neatly rubbed away the side leaving a green colour on all the flattened surface planes. I need to find out how this happened...
Anyway I stopped here today and leaving it alone until tomorrow as I might overpaint it too much and feel I need to proceed with caution so that I get the tones and colours right. So as usual I will have a look at it in the cold light of tomorrow over my breakfast coffee and see if it's OK so far...
New colour being used is Oxide of Chromium in addition to the colour mixes already in use.