The tooltip for clearing ruins indicates that clearing them should allow exploitation of the tiles, but it appears not to. While the tileset resets, the resources available to the city do not change, nor do the resource icons appear on the tile. 

To Reproduce: Ransack a city or outpost, then build a new city in that region (Found the new city on a non-ruined tile, there seems to be a separate bug where you can't clear ruins if you found on the ruined tile). The new city will have a "clear ruins" option, which can only be applied to a selected ruins tile. Select that tile. Once the clear ruins has completed, the graphical appearance of the tile will return to normal as expected, but the resources that tile should be providing are not available.

Expected Behavior: Clearing ruins should immediately provide the tile resources as if the ruins had never existed.