It's crashing (reproducibly) outside of the DLL. That means it is almost certainly down to bad graphical asset definitions for something you build that turn.
To determine this, here is what I did (because it's something anyone can do, so it would be a useful time saver if people could check this first if they get end turn CTDs):
1) From the save game set all cities to research (so nothing gets produced). End turn. If it still crashes it's not due to something being built, so go ahead and post the save game and request help.
2) If that prevented the crash we know it's due to something being built, so now to find out what. Two approaches you can take:
2.1) Binary chop. From the save game position set half the cities to research and leave the other half alone. End turn, check for CTD. If no CTD you know it was one of the cities you set to research, so reload the save game and set half of THOSE to research (so down to a quarter the original set). If it did CTD it was one of the ones we didn't set to research, so set half of THOSE to research and retry. Eventually you'll get down to one city. At that point you can report what it is that the building of causes a crash.
2.2) Suspicion! Look for anything unusual being built that turn. Set THAT city only to research and see if that prevents the crash.