▁grey ▁ph yll ite . ▁Hu ang li an ▁Form ation ▁in ▁south west ▁consists ▁mostly ▁of ▁sil ical ite . ▁ ▁The ▁north west ▁and ▁east ▁areas ▁are ▁not ▁well ▁differenti ated ▁in ▁the ▁Ed ia car an , ▁but ▁contain ▁met am orph ic ▁rocks ▁such ▁as ▁s ilt ite ▁le pt ite ▁and ▁act in ol ite ▁sch ist . ▁ ▁Camb rian ▁The ▁L int ian ▁group ▁contains ▁grey ▁met am orph osed ▁sand stone , ▁ph yll ite ▁and ▁sl ate ▁up ▁to ▁ 4   km ▁thick ▁in ▁western ▁F uj ian . ▁The ▁D ong k eng kou ▁Group ▁contains ▁met am orph osed ▁cal care ous ▁sand stone . ▁ ▁It ▁contains ▁Pro t osp ong ia ▁foss ils . ▁ ▁B eds ▁are ▁up ▁to ▁ 1   km ▁thick . ▁ ▁Ord ov ician ▁The ▁We if ang ▁Group ▁contains ▁dark ▁ph yll ite ▁and ▁lim estone ▁with ▁Did ym og ra pt us ▁gra pt ol ite ▁foss ils . ▁The ▁Lu of eng xi ▁Group ▁contains ▁met am orph osed ▁sand stone ▁in ▁which ▁Le iom argin ata ▁and ▁Con och it ina ▁inc erta ▁foss ils ▁have ▁been ▁found . ▁ ▁During ▁the ▁Sil ur ian ▁and ▁early ▁Dev onian ▁an ▁un con form ity ▁formed . ▁ ▁Dev onian ▁The ▁Dev onian ▁saw ▁terrest rial ▁depos its . ▁ ▁The ▁T ian wad ong ▁Form ation ▁contained ▁thick ▁con gl omer ate ▁b eds ▁with ▁plant ▁foss ils ▁like