It looks like a variation of Delta FL--a high compressive plastic that holds the finished flooring away from the concrete and leaves space for the moisture rising naturally through the basement floor to evaporate.

will it evaporate of does it 'rise naturally' until it hits the carpet then turns to mold...

I should have added the second part: By equalizing air pressure, the FL reduces the amount of water vapour moving through the concrete.

Googling around for potential problems with FL, the only one I've come across is that if the basement floods, water can get in the top of those thousands of dimples; in which case everything will have to be removed to get rid of the water. But after any flood that significant you would be doing the same thing with any water sensitive materials. Other users have mentioned a clicking sound when walking around on FL finished floors.