ILLUSTRATIONS. XI 



Page. 

 Pl.ATK XXVIII. I'liin sc(:tioiis()l inaf>iietitic nnd actinolitic slates from (lie Iron-I)eniiiig meiii- 



'•ei' -,01 



Fig. 1. Actinolitic slate. 



Fig. 2. Majiiietitic coucietiouaiy clicrt. 



Fig. ;>. liaiidcil magnetitic jas])ei-. 



Fig. 4. ActiiKilitic slate 

 XXIX. Thin scc^tions from the iron formation of the Auimikie series, and from Law- 



renci' connty, Qliio 5Q(j 



Fig. 1. C'oncretiouary cbcrt. 



Fig. 2. Actinolitic slate. 



Fig. 3. Actinolitic and sideritic slate. 



Fig. 4. Cherty iron carljonatc 

 XXX. Ore deposits 50g 



Fig. 1. Longitudinal section of scmth deposit, Montreal mine. 



Fig. '2. Longitndinal section of north deposit, Montreal mine. 



Fig. 3. Cross section of sonth depcsit, Montreal mine. 



Fig. 4. Cross section of south and north deposits, Montrt-al mine. 



Fig. 5. Longitudinal section of Pence mine. 



Figs. 6, 7, and 8. Cross sections of Pence mine. 

 XXXI. Ore deposits 5X0 



Fig. 1, Longitudinal section id' south depii.sit, ('idl>y mine. 



Fig. 2. Lougitu<linal section of north deposit, Colliy mine. 



Fig. 3. Cross sccticui of north and south deposits, Colhy mine. 



Fig. 4. Longitudinal section of Trimble mine. 



Fig. .">. Cro.ss section of Trinildi- mine. 



Fig. ti. Cross section of Minnewawa mine. 



Fig. 7. Theoretical section to show variation tioni on.iltereil cailionate 

 to ferruginous chert and ore bodies. 

 XXXII. Thin sections of grayw.ackes from rjiper-slatc member 512 



Fig. 1. Micaceous graywacke. 



Fig. 2. Biotitic and muscovitic graywacke. 



Fig. 3. Biotitic graywacke. 



Fig. 4. Biotitic and cbloritic graywacke. 



XXXIII. Thin sectiims showing development of mica-slates 514 



Fig. 1. Biotitic and muscovitic graywacke. 

 Fig. 2. Biotite-slate. 

 Fig. 3. Biotite-slate. 

 Fig. 4. Biotite-slate. 



XXXIV. Thin sections showing development of mica-schists and mica-slates 516 



Fig. 1. Muscovitic biotite-schist. • 



Fig. 2. Biotite-schist. 

 Fig 3. Biotite-slate. 

 Fig 4 Biotite-slate. 



XXXV. Thin section., from the Eastern area 518 



Fig. 1. Ferrnginou!-' chert anil qnartzite. 

 Fig. 2. Greenstone-conglomerate. 

 Fig. 3. Greenstone-conglomerate. 

 Fig. 4. The same, in )iolari/i-il li'jht. 



