NJDEP - NJGS - First Annual Report of the Geological Survey of the ...

32"1st. The'Oneida or' Shawangunk "' : Conglom6rate, occupyingthe elevated p0rtions of the Blue Mountain, and _4hieh i_comp0sed of a series of fine-grained sitieious grits," 60am_sandst0hes, and congloifierdtes rhado 'up of silicious inatter.t;rom fine Sand to pebbles of quartz thre_ quartcm of an ihchin diameter; the Hudson River Group, composed of darkcoloredslates, shales, thick-bedded and slaty ealcareou's grits_/o.; tl_ Utica Slate, composed of dark-colored and argillaceousslates, ft/rnishing in many places an e:¢eellent materialfoi roofing ; the Trenton and Black Rii:er Limestones ; CalciferousSand Rock, and Potsdam Shndstonc. The abovesubdivisions of the' Champlain Series, commencing with theHudson River Group, occupy chiefly the Kittatinny and Wall_kill v_.ileys.The metamorphmcroeks are gneiss, hornblende Slate, and"white crystalline limestone. Th¢ Ia_ter occurs chiefly in the//alley of the Wallkil!, between the Wawayanda and Wallkillmountains and the Poehuck and Pimple Hill range ; the twot'ormer constitute the principal part of the rocks of the moun.taih i-Kfiges,,aswell as several parallel belts of'the WaIlkillvalley." The' igncou_ rocks occu_rchiefly i-n the t'orm of intrusivev6ins_ dikes, _nd irregular masses of gi'anite, syenite, and'/tuartzose feldspathic rock, in the metamorphic, With the cxcep'-'tion of a porphyritic granite which occurs protruding through'the Hudson River Slate, and upheaving the Oneida Or Shaw:'angdnk Conglomerate of the' Blue Mountainnearfl;Fcmiles northeast c)f.Culver'sGap.Becmersv:ille_, * 4 ." ' " " ECONOMIC GEOLOGY.• Among the various ores and materials of c_onomiCalValue•occurring in the above formations are:, ,.Magnetic iron ore ;Specular iron ; . , .: LimOnite (hydre:is per6xido of iron); 'NEW JERSEY GEOLOGICAL SURVEY