No, not a Golden Age. In fact this is very late in the game, 9 turns from the end.
I do have to confess that I cheat in the placement of my cities, which follow a pattern. I explore a map first, determine where the cities will be placed, following my pattern as much as possible, and then restart the scenario at 4,000BC. Still, although I occasionally discover the iron resource during the time of my exploration, there is no way for me to predict the location of coal (to be able to build the Iron Works), or to otherwise affect a given city
to that degree. For example, in the case of Dallas, shown above, there is a perfect balance between grasslands and hills. You will note that the city has no excess food production. There is no way I could have planned that, especially since I'm not a Bean Counter in regard to this game.
I do remember that when I founded Dallas, it looked like it was going to be the place that would eventually build the Military Academy, or whatever it's called, because it had what I knew was going to be a very good balance between hills and grasslands. I always build the Military Academy in my most productive city, for the quickest building of Armies.
Well heck, I still have the save file, why don't I just attach it. Note that the attachment will also show how I like to pattern-place my cities, as well as everything else I like and don't like to do.