﻿650 
  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  quartz 
  and 
  plagioclase, 
  it 
  has 
  but 
  a 
  few 
  scattered 
  shreds 
  of 
  bluish 
  

   hornblende 
  to 
  represent 
  the 
  dark 
  silicates. 
  Near 
  the 
  ore 
  beds 
  

   occasional 
  garnets 
  appear, 
  and 
  these 
  in 
  the 
  drill 
  cores 
  are 
  regarded 
  

   as 
  a 
  favorable 
  indication. 
  This 
  rock 
  lacks 
  foliation 
  almost 
  entirely 
  

   and 
  would 
  be 
  at 
  once 
  called 
  a 
  very 
  acid 
  granite, 
  without 
  

   microscopic 
  examination. 
  We 
  have 
  only 
  met 
  it 
  in 
  this 
  area, 
  and 
  

   in 
  a 
  Mineville 
  drill 
  core 
  which 
  was 
  earlier 
  cited. 
  This 
  rock 
  is 
  

   extensively 
  faulted 
  and 
  superb 
  breccias 
  are 
  to 
  be 
  had 
  just 
  north 
  

   of 
  the 
  railway 
  station. 
  The 
  gneiss 
  is 
  crushed 
  into 
  fragments 
  of 
  

   all 
  sizes 
  and 
  cemented 
  by 
  chlorite 
  and 
  other 
  decomposition 
  pro- 
  

   ducts. 
  Faults 
  are 
  not 
  infrequent 
  in 
  the 
  mines 
  and 
  give 
  great 
  

   trouble, 
  often 
  cutting 
  the 
  bed 
  completely 
  off. 
  Here, 
  as 
  was 
  men- 
  

   tioned 
  earlier, 
  gulches 
  are 
  very 
  bad 
  for 
  its 
  continuance. 
  In 
  No. 
  

   7 
  slope 
  the 
  ore 
  was 
  lost 
  at 
  one 
  of 
  these 
  friction 
  breccias 
  ( 
  which 
  

   was 
  quite 
  naturally 
  regarded 
  as 
  a 
  trap 
  dike 
  until 
  seen 
  in 
  thin 
  sec- 
  

   tion), 
  and 
  a 
  drill 
  hole 
  over 
  a 
  thousand 
  feet 
  deep 
  failed 
  to 
  find 
  it 
  

   on 
  the 
  other 
  side. 
  This 
  famous 
  old 
  group 
  of 
  ore 
  bodies 
  deserves 
  

   detailed 
  study 
  and 
  plotting, 
  but 
  as 
  the 
  mine 
  maps 
  were 
  destroyed 
  

   in 
  a 
  fire 
  some 
  years 
  ago, 
  it 
  would 
  be 
  a 
  long 
  task 
  to 
  accumulate 
  

   the 
  necessary 
  data. 
  

  

  The 
  gneiss 
  is 
  sharply 
  cut 
  off 
  on 
  the, 
  east 
  by 
  one 
  of 
  the 
  finest 
  

   fault 
  scarps 
  in 
  the 
  entire 
  region. 
  From 
  Knob 
  pond 
  it 
  bears 
  

   away 
  with 
  a 
  general 
  course 
  of 
  north 
  thirty 
  degrees 
  east, 
  for 
  over 
  

   five 
  miles, 
  and 
  everywhere 
  is 
  marked 
  by 
  a 
  vertical 
  cliff, 
  or 
  where 
  

   this 
  has 
  weathered, 
  by 
  a 
  crushed 
  strip. 
  It 
  brings 
  the 
  limestone 
  

   series 
  against 
  the 
  gneisses 
  and 
  norite. 
  

  

  In 
  the 
  middle 
  of 
  the 
  great 
  limestone 
  area, 
  we 
  so 
  frequently 
  

   met 
  heavy, 
  massive 
  gneisses, 
  that 
  we 
  were 
  driven 
  to 
  the 
  conclusion 
  

   that 
  the 
  lower 
  series 
  comes 
  to 
  the 
  surface. 
  It 
  is 
  inclosed 
  by 
  the 
  

   limestones, 
  black 
  schists 
  and 
  gneisses. 
  No. 
  76, 
  at 
  the 
  southern 
  

   end, 
  is 
  biotite 
  gneiss 
  with 
  abundant 
  allanite. 
  

  

  Bulwagga 
  mountain 
  extends 
  down 
  from 
  Moriah, 
  affording 
  the 
  

   gneiss 
  area 
  of 
  the 
  northeast. 
  It 
  contains 
  the 
  usual 
  variety 
  of 
  

   pyroxene, 
  hornblende 
  and 
  biotite 
  gneisses. 
  The 
  general 
  strike 
  

   of 
  the 
  laminations 
  is 
  nearly 
  north 
  and 
  south. 
  In 
  the 
  northwest 
  

   corner 
  of 
  the 
  area 
  along 
  the 
  east 
  and 
  west 
  road 
  (38, 
  89, 
  etc.) 
  the 
  

   rocks 
  seem 
  to 
  afford 
  an 
  imperceptible 
  gradation 
  from 
  the 
  typical 
  

   light-colored 
  gneisses, 
  into 
  the 
  dark 
  basic 
  ones 
  of 
  the 
  limestone 
  

   series 
  with 
  limestones, 
  and 
  thence 
  into 
  gneissoid 
  forms 
  of 
  

   anorthosite. 
  

  

  