I really recommend you link to the USGS page and explore the map and the information which is provided. There are hotspots on the map with lots of detailed information about farming in the valleys - just like the one Mark cycled through today. It is also possible to look at how landcover changed in the area between 1977 and 1987.'Back on the road' again......Mark will almost certainly have cycled past this feature, known as the Zanjan - Tabriz fault, either today or yesterday. It is visual proof of the stress which the earth's crust is under in this part of the world.
Finally, I notice that the GPS tracker places Mark at Takestan this evening. Here is a lovely sunset view I found on Flickr of "sunset near Takestan, Iran" ...I hope the view is this good from Mark's tent tonight!