Texture Quality - Manual.
Texture Resolution - Extra.
Normal Map Resolution - Extra.
Terrain Detail - Extra.
Image Quality - Extra.
Looks like these 5 settings can be tweaked.
GTA IV is another such game where upping certain settings offers little visual gain, but consumes absurdly high resources.
Try tweaking these settings, if any improvement is there. If the game is storing too many too large textures in memory, it could have a problem.
I have never played this game myself - certainly not on a 970 - so I can't say anything more specific than that.
If you can - post another screenshot with these settings all at lowest. Also try restarting the game after changing the settings(may not be required).
Also, you could turn off antialiasing. 1080p is a large resolution, using antialiasing on such a resolution is a waste unless you have a 27" monitor or something.