Odd....could have sworn that I posted this yesterday, but can't see my post.
I was wondering how the limited resource mod worked, so far I've played 2 games on snail pace. In one of those games I found some marble, built a quarry and the next turn it was depleted, at that point I had 4 cities and nothing that I was building made use of marble.
In a second game I found stone, built a quarry on it and 4 turns later it was depleted, only 3 cities this time and again nothing that I was building required stone, replaced the stone with World Builder and it depleted about 4 turns later.
I'd find it odd that any resource would deplete so quickly even on a faster game speed, but considering that I was playing on snail speed then surely resources should take far longer to deplete?