LAKE    SUPERIOR   REGION.  151 
The  descending  succession  in  the  Pewabic  mine  is  as  follows: 
Feet, 
Jasper  and  ore,  containing  Pewabic  ore  1  iody 215 
Gray  slates 112 
Quartz. 
Gray  slate. 
Quartzite 77 
Quartz  and  slate. 
Slate  conglomerate 50 
Red  slate 77 
Quartz  and  gray  slate. 
Quartzite. 
Quartz  and  sand. 
Slate  conglomerate. 
Quartz  conglomerate 116 
Red  slate. 
Jasper. 
Red,  gray  slate. 
Limestone. 
The  ore  bodies  are  found  in  beds  of  banded  lean  jasper,  which  is 
always  an  invariable  associate  of  the  richer  ore,  and  it  may  occur 
anywhere  within  the  jaspery  horizon.  The  rich  ore  often  appears  to 
be  a  part  and  parcel  of  the  general  stratification  of  the  lean  ore 
encompassing  it.  Not  infrequently  one  finds  spots  which  are  appar- 
ently in  the  transition  state  from  the  lean  jaspery  ore,  as  though  the 
ore  body  was  charged  with  a  solution  which  was  gradually  dissolving 
out  the  silica  from  the  adjacent  jasper.  There  is  invariably  a  notable 
pitch  to  the  ore  bodies,  and  it  is  generally  to  the  west  at  an  angle  of 
30°  to  50°.  Connected  with  some  of  the  ore  bodies  are  well-defined 
hanging  or  foot  walls  of  so-called  soapstone,  but  often  when  there 
are  no  well-defined  walls,  the  ore  body  being  found  in  the  jasper,  the 
ore  carries  a  minimum  of  phosphorus,  as  exemplified  at  the  Millie, 
Pewabic,  Cyclops,  Aragon,  and  S.  E.  Vulcan  mines.  The  productive 
portions  of  the  range  appear  to  be  located  at  the  points  where  the 
formation  has  been  faulted,  eroded  deeply,  or  sharply  folded. 
Smyth,66  in  1893,  describes  a  contact  between  the  lower  quartzite 
of  the  Lower  Huronian  and  the  underlying  granite  at  Republic,  Mich. 
Below  the  lowest  exposures  of  magnetite-actinolite  schist  are  ex- 
posures of  the  lower  quartzite,  and  below  this,  hanging  upon  the 
northern  flank  of  the  granite,  is  a  conglomerate  containing  very 
numerous  well-rounded  bowlders  of  granite  and  gneiss,  identical  with 
the  rocks  immediately  below.  It  is  concluded  that  this  conglomerate, 
from  its  position,  can  not  possibly  belong  to  the  Upper  Huronian.  and 
that  it  is  a  true  basal  conglomerate  of  the  Lower  Huronian. 
Hubbard,117  in  1804,  o-ives  two  geological  cross  sections  of  the  Ke- 
weenawan  series  in  the  vicinity  of  the  Calumet  and   Ilecla  and  the 
