"Green fields is one of the largest discoveries of this...

^{"Green fields is one of the largest discoveries of this century."}

Well, just to be sure that you don't lose your pay cheque betting with your mates at the pub - your post reads like maybe you are confusing the general exploration term "greenfields" with the Green Fields toll treat mill. One could assume Mr Google had a hand in that. Unless you would like to enlighten me otherwise.