14 



12' 



lO' 





fC/uizy to Riihniornl.Mitpfjt'd with 

 Silaruui Lit theArcUc aiui with ( a/n 

 hriiuL (uul lowefOrdovuiart in t}ie 



Roiky Moiuit4iins of the Ihiilttl Stairs) 



18 



r 



CAMBRIAN AND LOWER ORDOVICIAN 



(i iifiitiiiiNi to Beck/iituitowiiiUi funis 

 ot^the CordiUria invhuJes Sihuiaji dnJ 

 ufififr Oiihi vifKinl 



/jdkr Suftet'ior reffion 



y 



O 



O 

 N 

 O 



a:< 



UJ 



I- 

 O 



Q. 



O 



O 

 N 



°<' 



I 

 O 



< 



O 

 O 





('ofdi/frT-fiii I -pgion 



KEWEENAWAN 



(Liiva flows, sedinifiils.and Liitiusive rocliH; 

 tneluJes Nipiy on' series of Lake Superior- 

 ity ion) 



''.'■■'■'' ■!■'!( 

 '.■.;l',;\:.;i;'r 



UPPER HURONIAN 



(Aniniikte umi nfuivnltuUs in Lake 

 Siipeiiof n'lfion ii/i<J inlfiusivf rocks) 



MIDDLE AND LOWER HURONIAN 



(Srdinifn/<ny nn<l intriisivf ntcks i/i 

 Lake Superior retfion) 



L.> />A r^J />J ("VJ I'J lA lyi u 



z 

 < 



UJ 



o 

 tr 

 < 



KEEWATIN 



(Olde'St pre-Canihrian ofthe'Lake' 

 Superior rec/ion.largeiy bcusic lavas) 



iijg^m 



LAURENTIAN 



(Aridie pluionu- rocks intrusive in 

 Keewatin in Wisconsin,.Michi*fan, 

 (tn/t Minnesota j 



Geologic drafting by Henry S, Selden 



\•^2° 



130" 



128" 



21a 



BELT SERIES 



iHcIt series id western /y'orky 

 Mount, lins; Xeeitle Mountiiins 

 1/1 "Np (dsiiiitliwesiei'ii ( '(il<>rii<lii_ 

 (jiKirl ■: lies III' the I'iiilti iiiut 

 II n siite/i iiinii II ta iiisj 



Kasb'fii ( 'iiriada 



^ 



HASTINGS AND GRENVILLE 



fLunestones onil nssocuifed rocks 

 ine-astern CcmadaJ 



GNEISSES, SCHISTS, AND 

 METAMORPHOSED SEDIMENTS 

 (Supposed pre CiLinbrianipossibly 

 in pen I Pnleozotc nini Mesozoic) 



\ 



(' a Hilda 



21 



LATE? PRE-CAMBRIAN 

 UNCLASSIFIED 



(Athiibasca -JVustopoka series. 

 Avafon i/roup.fjold t>e^nng 

 Me<]iini<i series, ainl other little 

 disturbed strata ft 'arn brian") in 

 Caruhda,:/ 



22 



EARLIER? PRE-CAMBRIAN 

 UNCLASSIFIED 



(Metamorphosed iron -bearing rocks. 

 Hiirx>nian", throughout Canada J 



;2^b. 



J 



"LAURENTIAN" 



iJnersses ainl platunit- rocks thr-oiigli 

 out ( 'anada and the Arctic,- Tllsronsin 

 \Tiiniesi>ui,fuul North Dakx'tiz/ 



> UNDIFFERENTIATED PRE-CAMBRIAN 



((Gneisses oftheAppalachians.Missoiu-i, 

 Tea-as. Arizorva, and the Kocky Mountains 

 of the United States; iTvclxide^ plutonie 

 igneous rooks where not separate^ mapped) 



J 



126° 



124° 



122" 



120° 



U8° 



U6° 



