▁the ▁Ta con ic ▁or ogen y . ▁The ▁collision ▁closed ▁the ▁I ap et us ▁Ocean ▁and ▁ob duct ed ▁the ▁Laurent ian ▁contin ental ▁margin ▁under ▁the ▁two ▁island ▁ar cs . ▁The ▁process ▁produced ▁a ▁strange ▁bul ged ▁up ▁area ▁of ▁mant le ▁material ▁to ▁the ▁surface ▁as ▁per id ot ite ▁in ▁Gros ▁Mor ne ▁National ▁Park , ▁essentially ▁the ▁only ▁area ▁on ▁the ▁Earth ' s ▁surface ▁where ▁mant le ▁material ▁is ▁present ▁as ▁cool , ▁cry st all ized ▁rock . ▁It ▁also ▁created ▁an ▁o phi ol ite ▁zone ▁where ▁ocean ic ▁cr ust ▁was ▁preserved ▁on ▁land . ▁ ▁Ge olog ists ▁group ▁the ▁rocks ▁in ▁this ▁area ▁into ▁the ▁H umber ▁Zone ▁and ▁the ▁D unn age ▁Zone , ▁with ▁the ▁D unn age ▁Zone ' s ▁southern ▁edge ▁defined ▁by ▁the ▁G ander ▁River ▁Ult rab as ic ▁B elt . ▁The ▁neighbor ing ▁G ander ▁Zone ▁has ▁s ilt stone , ▁sh ale ▁and ▁quart z ▁sand stone ▁as ▁well ▁as ▁de formed ▁rocks ▁and ▁gran ite . ▁The ▁sed iments ▁were ▁depos ited ▁on ▁the ▁contin ental ▁margin ▁during ▁the ▁closure ▁of ▁the ▁I ap et us ▁Ocean . ▁ ▁By ▁ 3 5 6 ▁million ▁years ▁ago , ▁G ond w ana ▁coll ided ▁with ▁Eur amer ica , ▁closing ▁the ▁R he ic ▁Ocean ▁and ▁creating ▁the ▁super cont inent ▁P ange a , ▁which ▁left ▁New found land ▁and ▁the ▁A val onian ▁micro cont inent ▁( also