﻿130 
  D. 
  D. 
  Condit 
  — 
  Deep 
  Wells 
  at 
  Findlay, 
  Ohio. 
  

  

  samples 
  at 
  intervals 
  of 
  three 
  or 
  four 
  feet, 
  which 
  were 
  painstak- 
  

   ingly 
  washed 
  by 
  the 
  driller 
  thus 
  losing 
  all 
  of 
  the 
  mineral 
  

   powder. 
  No 
  rock 
  particles 
  were 
  obtained. 
  

  

  The 
  samples, 
  fifty-five 
  in 
  number, 
  are 
  fairly 
  uniform 
  as 
  to 
  

   mineral 
  composition 
  except 
  the 
  ones 
  from 
  near 
  the 
  bottom 
  of 
  

   the 
  hole, 
  which 
  consist 
  largely 
  of 
  flakes 
  of 
  iron 
  and 
  heavy 
  

   minerals. 
  Quartz 
  and 
  feldspars 
  are 
  the 
  principal 
  constituents. 
  

   The 
  feldspars 
  are 
  principally 
  orthoclase, 
  microcline 
  and 
  acid 
  

   plagioclase. 
  A 
  few 
  microperthitic 
  intergrowths 
  were 
  seen. 
  

   The 
  quartz 
  has 
  inclusions 
  of 
  rutile. 
  Green 
  hornblende 
  and 
  

   biotite 
  are 
  next 
  to 
  quartz 
  and 
  feldspar 
  in 
  order 
  of 
  abundance. 
  

   These 
  are 
  not 
  uniformly 
  distributed, 
  being 
  abundant 
  in 
  some 
  

   samples 
  and 
  practically 
  wanting 
  in 
  others. 
  Such 
  irregularity 
  

   in 
  their 
  occurrence 
  may 
  signify 
  a 
  banded 
  gneissoid 
  structure 
  

   for 
  the 
  rock, 
  but 
  it 
  must 
  be 
  remembered 
  that 
  the 
  sand 
  bailer 
  

   is 
  not 
  an 
  accurate 
  sampling 
  device, 
  and 
  in 
  dumping, 
  mica 
  and 
  

   hornblende 
  would 
  be 
  the 
  most 
  likely 
  materials 
  to 
  be 
  washed 
  

   away 
  and 
  lost. 
  Minerals 
  present 
  in 
  lesser 
  amounts 
  are 
  titanite, 
  

   apatite, 
  garnet, 
  muscovite, 
  zircon, 
  and 
  a 
  mineral 
  probably 
  diop- 
  

   side, 
  together 
  with 
  chlorite, 
  sericite, 
  kaolinite, 
  and 
  other 
  alter- 
  

   ation 
  products. 
  There 
  are 
  several 
  rusty 
  oxidized 
  samples 
  from 
  

   various 
  depths 
  which 
  evidently 
  came 
  from 
  shear 
  zones 
  or 
  joint 
  

   planes, 
  but 
  aside 
  from 
  these 
  decomposition 
  is 
  not 
  advanced 
  

   even 
  in 
  the 
  upper 
  portion. 
  

  

  Garnet 
  is 
  found 
  rather 
  sparingly 
  in 
  the 
  upper 
  portion, 
  but 
  

   the 
  samples 
  at 
  and 
  near 
  the 
  bottom 
  of 
  the 
  hole 
  have 
  much 
  gar- 
  

   net, 
  together 
  with 
  zircon, 
  titanite 
  and 
  other 
  heavy 
  minerals. 
  

   Titanite 
  is 
  more 
  plentifully 
  and 
  uniformly 
  distributed 
  through- 
  

   out 
  the 
  rock, 
  and 
  in 
  some 
  samples 
  probably 
  constitutes 
  as 
  much 
  

   as 
  four 
  per 
  cent. 
  Muscovite 
  is 
  present 
  in 
  only 
  a 
  few 
  samples. 
  

   One 
  sample, 
  lacking 
  hornblende 
  and 
  having 
  considerable 
  mus- 
  

   covite 
  and 
  little 
  biotite, 
  may 
  have 
  come 
  from 
  a 
  pegmatite 
  dike. 
  

  

  The 
  information 
  at 
  hand 
  does 
  not 
  warrant 
  sweeping 
  conclu- 
  

   sions 
  as 
  to 
  the 
  relations 
  of 
  this 
  rock, 
  but 
  it 
  is 
  believed 
  that 
  its 
  

   composition 
  is 
  consistent 
  with 
  that 
  of 
  granite. 
  In 
  the 
  upper 
  

   portion 
  the 
  rock 
  is 
  typical 
  hornblende 
  granite. 
  Toward 
  the 
  

   bottom 
  the 
  quantity 
  of 
  dark 
  minerals 
  becomes 
  larger, 
  but 
  is 
  

   not 
  prohibitive, 
  and 
  it 
  is 
  doubtful 
  whether 
  the 
  name 
  grano- 
  

   diorite 
  should 
  be 
  used 
  even 
  for 
  this 
  most 
  basic 
  portion. 
  The 
  

   somewhat 
  abundant 
  occurrence 
  of 
  titanite 
  and 
  garnet 
  might 
  

   be 
  regarded 
  as 
  militating 
  against 
  the 
  conclusion 
  that 
  the 
  rock 
  

   is 
  igneous, 
  but 
  these 
  minerals 
  may 
  be 
  accounted 
  for 
  by 
  suppos- 
  

   ing 
  that 
  sedimentary 
  masses 
  were 
  caught 
  up 
  and 
  blended 
  with 
  

   the 
  granite 
  magma. 
  This 
  view 
  is 
  supported 
  by 
  the 
  fact 
  that 
  

   these 
  minerals 
  are 
  more 
  or 
  less 
  localized. 
  

  

  It 
  is 
  probable 
  that 
  the 
  rock 
  has 
  a 
  gneissoid 
  structure. 
  JSTo 
  

   evidence 
  of 
  this 
  was 
  noticed 
  in 
  the 
  microscopic 
  examination 
  of 
  

   the 
  samples, 
  but 
  there 
  is 
  an 
  alteration 
  of 
  light 
  and 
  dark 
  samples 
  

   which 
  suggests 
  a 
  banded 
  rock. 
  

  

  