Why do some tiles have red "chips" on them in Civilization 5?

In Civilization 5 some of the hexes have a little red splotch on them, especially during the early game.

I've been going under the assumption that these signify strategic resources that I don't know how to use yet - they might be handy later once I discover Oil or whatever.

Is this remotely correct?


This is a graphics bug. It was supposedly fixed during the october patch -- have you installed it? Specifically:

Map – Terrain caching fix that could cause problems for certain video cards (the "glowing red orbs" seen on the map are an indicator of this).