▁which ▁was ▁owned ▁by ▁R ew a ▁Co al fields ▁Limited , ▁was ▁national ized ▁in ▁ 1 9 7 3 . ▁ ▁The ▁coal field ▁U mar ia ▁Co al field ▁is ▁a ▁part ▁of ▁Central ▁India ▁Co al fields . ▁The ▁latter ▁is ▁spread ▁over ▁the ▁districts ▁of ▁S urg u ja , ▁K ori ya ▁( both ▁in ▁Ch h att is gar h ), ▁Shah d ol ▁and ▁U mar ia ▁( both ▁in ▁Mad h ya ▁Pr adesh ). ▁There ▁are ▁four teen ▁coal fields ▁in ▁this ▁group , ▁namely ▁Kor ar , ▁U mar ia , ▁Joh illa ( Now roz abad ), ▁So h ag pur , ▁Son hat , ▁J h il im ili , ▁Ch ir imi ri , ▁Send urg ar h , ▁Kore agar h , ▁Dam ham unda , ▁Pan ch bah ini , ▁Has de o - Ar and , ▁Lak han pur ▁and ▁B ish r amp ur . ▁The ▁group ▁covers ▁an ▁area ▁of ▁about ▁ ▁with ▁estimated ▁res erves ▁of ▁ 1 5 , 6 1 3 . 9 8 ▁million ▁t onnes . ▁The ▁depos its ▁are ▁at ▁a ▁depth ▁of ▁ 0 - 1 2 0 0 ▁meters . ▁ ▁Therefore , ▁extra ction ▁is ▁mainly ▁am enable ▁to ▁under ground ▁min ing ▁except ▁a ▁few ▁blocks ▁in ▁eastern ▁part ▁of ▁these ▁coal fields ▁which ▁have ▁open cast ▁potential . ▁ ▁In ▁U mar ia ▁Co al field , ▁the ▁Lower ▁G ond w ana