shsed.]  NOTES    ON    THE    COPPER    MINES    OF    VERMONT.  197 
bj  south  and  225  feet  to  the  north,  while  a  third  level  at  160  feet  in  depth 
afforded  the  main  stoping  ground.  A  wing  60  feet  deep  connects 
this  level  with  225-foot  adit  workings.  In  1898  a  crosscut  tunnel 
1,310  feet  long  was  finished,  opening  up  the  ore  body  225  feet  below 
the  outcrop.     There  is  578  feet  of  drifting  on  this  level. 
lite  ore  body. — The  ore  body  is  interlaminated  with  micaceous  schists, 
forming  a  lens  whose  axis  pitches  gently  to  the  north.  The  foot-wall 
rock  is  harder  and  more  quartzose  than  the  hanging- wall  material.  The 
foot  wall  is  smooth,  regular,  and  in  the  open-cut  workings  is  seen  to 
"form  a  well-defined  plane  with  a  dip  of  70°  E.  The  ore  body  has  a 
northeast-southwest  course.  The  ore  lens  is  said  to  pinch  out  along 
the  outcrop  at  a  point  about  700  feet  south  of  the  shaft.  It  varies 
from  25  to  100  feet  in  thickness  along  this  open  cut.  On  the  225-foot 
level  the  ore  is  35  feet  between  walls,  but  only  a  thickness  of  24  feet 
las  been  extracted.  As  seen  in  the  open  cut  the  ore  body  is  a  com- 
pound one,  with  a  slab  of  schist  2  to  5  feet  thick  separating  the  main 
mass  from  a  hanging-wall  layer. 
The  ore  is  similar  in  mineralogic  character  to  that  of  the  other 
deposits  of  the  belt.  The  average  composition  has  already  been  given. 
The  best  ore  occurs  in  the  central  6  to  8  feet  of  the  ore  body,  and 
becomes  lower  grade  as  the  walls  are  approached,  the  ore  passing 
gradually  into  country  rock.  This  feature  is  particularly  well  shown 
in  the  foot  wall  at  the  north  end  of  the  225-foot  level.  Samples  from 
each  section  of  the  vein  were  assayed,  and  yielded  as  follows: 
Copper  in  ore  from  Elizabeth  mine. 
Per  cent. 
Hanging-wall  portion 2.30 
Central  portion  of  vein 4.64 
Foot-wall-  portion  of  vein. . .  „ 4.28 
Each  sample  represents  a  width  of  8  feet.  As  already  noted  this 
ore  is  low  in  silica,  compared  with  other  properties  in  the  State.  The 
total  amount  of  ore  developed  is  estimated  by  private  parties  at 
275,000  tons  of  3  per  cent  material.  In  working  this  mine  in  1899 
and  1900  the  ore  was  broken,  sorted  into  two  grades,  and  the  richer 
portion,  called  No.  1  ore  and  carrying  about  4  per  cent  copper,  and 
amounting  to  30  to  35  per  cent  of  the  total  tonnage,  was  hauled  to 
the  railroad,  and  shipped.  The  second-class  ore,  averaging  but  2  per 
cent  copper,  was  placed  on  roast  heaps  for  local  treatment.  Only  5 
per  cent  of  waste  was  produced  in  sorting  the  ore. 
CORINTH  MINES. 
The  mines  of  Corinth  Township  are  located  about  11  miles  north  of 
Copperfield,  and  7  miles  west  of  the  Boston  and  Maine  Railroad.  The 
ore  bodies  lie  in  gneissoid  rocks  somewhat  harder  than  the  micaceous 
