﻿LATJRENTIAN 
  LIMESTONES 
  OF 
  NORTH 
  AMERICA. 
  91 
  

  

  the 
  form 
  of 
  a 
  small 
  lenticular 
  bed, 
  in 
  immediate 
  contact 
  with 
  a 
  

   bed 
  of 
  magnetic 
  iron 
  ore 
  {Ibid, 
  page 
  693). 
  Small 
  veins 
  filled 
  

   with 
  cubic 
  aud 
  magnetic 
  iron 
  pyrites, 
  copper 
  pyrites 
  and 
  blende, 
  

   with 
  a 
  little 
  calcite, 
  are 
  found 
  traversing 
  a 
  magnesian 
  limestone 
  

   in 
  Macloc. 
  

  

  [In 
  another 
  locality 
  in 
  the 
  same 
  township 
  similar 
  veins, 
  having 
  

   a 
  gangue 
  of 
  mixed 
  calcite, 
  bitter-spar 
  and 
  quartz, 
  carry 
  besides 
  

   copper 
  pyrites, 
  galena 
  and 
  the 
  two 
  species 
  of 
  iron 
  pyrites 
  just 
  

   mentioned, 
  mispickel 
  and 
  argentiferous 
  faJilerz, 
  the 
  latter 
  species 
  

   predominating 
  and 
  being 
  associated 
  with 
  a 
  little 
  gold. 
  The 
  mis- 
  

   pickel 
  of 
  the 
  locality 
  just 
  described 
  contains 
  a 
  trace 
  of 
  cobalt. 
  

   The 
  same 
  mineral 
  is 
  found 
  in 
  several 
  other 
  localities 
  in 
  that 
  

   vicinity, 
  which 
  moreover 
  affords 
  mljphuret 
  of 
  antimony 
  in 
  small 
  

   quantities 
  disseminated 
  in 
  dolomite, 
  and 
  in 
  one 
  instance 
  associated 
  

   with 
  tremolite.] 
  

  

  [Bismuthlne.— 
  The 
  sulphuret 
  of 
  bismuth 
  is 
  found 
  in 
  crystalline 
  

   masses 
  of 
  considerable 
  size 
  in 
  a 
  vein 
  cutting 
  a 
  plumbaginous 
  lime- 
  

   stone 
  in 
  Lake, 
  in 
  the 
  province 
  of 
  Ontario. 
  It 
  is 
  imbedded 
  in 
  quartz, 
  

   and 
  immediately 
  associated 
  with 
  plumbago 
  and 
  brown 
  tourmaline, 
  

   delicate 
  prisms 
  of 
  which 
  are 
  occasionally 
  found 
  penetrating 
  the 
  

   bismuthine. 
  Minute 
  portions 
  of 
  native 
  bismuth 
  are 
  occasionally 
  

   met 
  with 
  in 
  the 
  vein, 
  and 
  carbonate 
  of 
  bismuth, 
  probably 
  from 
  the 
  

   decomposition 
  of 
  the 
  sulphuret, 
  occurs 
  near 
  the 
  surface. 
  This 
  vein 
  

   belongs 
  to 
  the 
  third 
  class, 
  already 
  described, 
  and 
  in 
  some 
  parts 
  by 
  

   an 
  admixture 
  of 
  mica 
  and 
  calcite 
  passes 
  into 
  an 
  aggregate 
  which 
  

   might 
  be 
  mistaken 
  for 
  a 
  coarsely 
  crystalline 
  limestone. 
  These 
  

   calcareous 
  portions 
  of 
  the 
  vein 
  are 
  pinkish 
  in 
  color, 
  with 
  yellow 
  

   phiogopite, 
  aud 
  contain 
  crystalline 
  masses 
  of 
  iron 
  pyrites.] 
  

  

  Sulphuret 
  of 
  Molybdenum. 
  — 
  This 
  species, 
  as 
  mentioned 
  in 
  the 
  

   Geology 
  of 
  Canada, 
  pages 
  503 
  and 
  754, 
  occurs 
  in 
  several 
  locali- 
  

   ties 
  in 
  the 
  Laurentian 
  rocks. 
  In 
  the 
  vicinity 
  of 
  Balsam 
  Lake 
  it 
  is 
  

   found 
  in 
  small 
  quantities, 
  associated 
  with 
  scapolite, 
  pyroxene 
  and 
  

   iron 
  pyrites, 
  in 
  a 
  huge 
  vein 
  of 
  quartz 
  which 
  traverses 
  the 
  crystal- 
  

   line 
  limestones 
  of 
  that 
  region. 
  

  

  [Gold. 
  — 
  The 
  occurrence 
  of 
  native 
  gold 
  has 
  already 
  been 
  men- 
  

   tioned 
  on 
  page 
  66. 
  Small 
  portions 
  of 
  the 
  precious 
  metal 
  have 
  

   also 
  been 
  detected 
  in 
  assays 
  of 
  pyritiferous 
  quartz 
  from 
  Belmont, 
  

   and 
  it 
  is 
  said 
  in 
  quartz 
  from 
  other 
  localities, 
  and 
  also 
  associated 
  

  

  