﻿278 
  E. 
  B. 
  Branson 
  — 
  Geologic 
  Section 
  in 
  Missouri. 
  

  

  low 
  mentions 
  the 
  great 
  irregularities 
  in 
  thickness 
  of 
  the 
  

   St.* 
  Peter 
  bnt 
  does 
  not 
  tell 
  of 
  the 
  patchiness 
  of 
  its 
  rem- 
  

   nants. 
  

  

  Acknowledgments. 
  — 
  My 
  first 
  work 
  in 
  Callaway 
  

   Comity 
  was 
  made 
  easy 
  by 
  Mr. 
  D. 
  K. 
  Greger 
  who 
  knew 
  

   practically 
  every 
  ontcrop 
  of 
  Devonian 
  of 
  importance 
  in 
  

   that 
  comity. 
  Mr. 
  Greger 
  and 
  several 
  of 
  my 
  advanced 
  

   students 
  have 
  worked 
  with 
  me 
  on 
  various 
  parts 
  of 
  the 
  

   section 
  here 
  discussed 
  and 
  many 
  of 
  the 
  details 
  and 
  larger 
  

   features 
  were 
  first 
  brought 
  to 
  my 
  attention 
  by 
  them. 
  

  

  University 
  of 
  Missouri, 
  

   Columbia, 
  Mo. 
  

  

  Aet. 
  XXI. 
  — 
  On 
  the 
  Occurrence 
  of 
  Byscrasite 
  in 
  Austra- 
  

   lia; 
  by 
  Geoege 
  Smith. 
  

  

  The 
  only 
  discovery 
  of 
  dyscrasite 
  in 
  Australia 
  was 
  

   made 
  in 
  the 
  Consols 
  Mine 
  at 
  Broken 
  Hill. 
  The 
  lode 
  in 
  

   this 
  mine 
  is 
  a 
  true 
  fissure 
  vein 
  having 
  no 
  known 
  connec- 
  

   tion 
  with 
  the 
  main 
  lode 
  of 
  the 
  district 
  and 
  whose 
  ores 
  

   were 
  dissimilar 
  in 
  almost 
  every 
  respect. 
  

  

  The 
  Consols 
  lode 
  passed 
  through 
  alternate 
  bands 
  of 
  

   amphibolite 
  and 
  crystalline 
  schists, 
  but 
  was 
  only 
  ore- 
  

   bearing 
  in 
  the 
  former. 
  The 
  fissure, 
  however, 
  continued 
  

   through 
  the 
  schist, 
  but 
  though 
  driven 
  on 
  in 
  this 
  rock 
  for 
  

   many 
  hundred 
  feet 
  was 
  never 
  found 
  to 
  contain 
  more 
  than 
  

   a 
  thin 
  seam 
  of 
  flucaii 
  assaying 
  traces 
  of 
  silver. 
  Where 
  

   the 
  lode 
  entered 
  the 
  amphibolite 
  it 
  opened 
  out 
  immedi- 
  

   ately, 
  the 
  gangue 
  being 
  limonite 
  in 
  the 
  oxydised 
  zone 
  and 
  

   siderite 
  with 
  calcite 
  below; 
  this 
  change 
  was 
  found 
  at 
  a 
  

   vertical 
  depth 
  of 
  about 
  130 
  feet. 
  

  

  The 
  principal 
  ores 
  were 
  stronieyerite 
  (by 
  far 
  the 
  most 
  

   important 
  in 
  point 
  of 
  productiveness), 
  fahlerz, 
  dyscra- 
  

   site, 
  chloro-antimoniate 
  of 
  silver, 
  cerargyrite, 
  iodyrite 
  

   and 
  some 
  galena, 
  with 
  small 
  quantities 
  of 
  stephanite 
  and 
  

   pyrargyrite. 
  Sternbergite 
  and 
  proustite 
  were 
  also 
  met 
  

   with. 
  The 
  stronieyerite 
  averaged 
  between 
  9,000 
  and 
  

   10,000 
  ounces 
  of 
  silver 
  per 
  ton, 
  and 
  the 
  fahlerz 
  6,000 
  to 
  

   7,000 
  ounces, 
  but 
  it 
  is 
  proposed 
  to 
  refer 
  herein 
  only 
  to 
  

   the 
  dyscrasite 
  and 
  the 
  chloro-antimoniate, 
  as 
  these 
  ores 
  

   were 
  closely 
  associated, 
  the 
  latter 
  being 
  the 
  result 
  of 
  the 
  

  

  