Many thanks for your response, and for the coordinates. I had noticed the ruin east of Kizilagac, but not the one to its SSW. Both measure between 25-30 m in length, and whereas this might be close to the size of a church, they cannot be monasteries in themselves. If not more recent Kurdish ruins, they might be outlying chapels or barns attached to a nearby monastery.
Have you any information at all about the Red Monastery?
Any help in all or any of these queries is appreciated.