Question: ark what can damage stone walls?
Answer: The Stone Wall is treated as a stone structure and can only be damaged by: Metal Weapons (5%) Tek Sword (~218%) Explosives (150%) Ballista Turret (40%) Cannon (~137%) Therizinosaur (Headbutt only, ~2%) ... 
These can damage stone, but can not damage auto turrets: Giganotosaurus (15%) Tek Rifle (~50%) Rock Elemental.