﻿154 
  Scientific 
  Intelligence. 
  

  

  detailed 
  Pigeon 
  Point 
  Plate 
  shows 
  any 
  formations 
  intervening 
  

   between 
  the 
  Puckwunge 
  conglomerate 
  or 
  sandstone 
  and 
  the 
  

   Animikie 
  ; 
  and 
  the 
  map 
  is 
  according 
  to 
  the 
  writer's 
  experience 
  a 
  

   correct 
  expression 
  of 
  the 
  relationship 
  which 
  prevails 
  in 
  the 
  

   Thunder 
  Bay 
  district. 
  

  

  The 
  relation 
  of 
  the 
  Carltonian 
  Anorthosites 
  to 
  the 
  Duluth 
  

   gabbro 
  is 
  not 
  freely 
  discussed 
  in 
  the 
  report, 
  but 
  it 
  seems 
  to 
  be 
  

   assumed 
  that 
  they 
  are 
  the 
  same 
  formation. 
  This 
  again 
  is 
  incon- 
  

   sistent 
  with 
  the 
  view 
  that 
  the 
  Beaver 
  Bay 
  diabase 
  is 
  the 
  surface 
  

   equivalent 
  of 
  the 
  gabbro, 
  for 
  the 
  writer 
  has 
  shown 
  that 
  both 
  at 
  

   Beaver 
  Bay 
  and 
  at 
  Carlton 
  Peak, 
  the 
  rocks 
  now 
  mapped 
  as 
  

   Beaver 
  Bay 
  diabase 
  repose 
  upon 
  the 
  worn 
  surface 
  of 
  the 
  anortho- 
  

   site. 
  It 
  is 
  futile 
  to 
  claim 
  that 
  the 
  extensive 
  areas 
  of 
  anorthosite 
  

   seen 
  under 
  the 
  lavas 
  at 
  Beaver 
  Bay 
  are 
  inclusions 
  in 
  the 
  lava, 
  and 
  

   the 
  claim 
  is 
  reduced 
  to 
  an 
  absurdity 
  when 
  the 
  mountain 
  mass 
  of 
  

   anorthosite 
  at 
  Carlton 
  Peak 
  is 
  considered. 
  The 
  anorthosite 
  is 
  

   petrographically 
  distinct 
  from 
  the 
  gabbro; 
  it 
  shows 
  none 
  of 
  the 
  

   contact 
  phenomena 
  of 
  the 
  gabbro 
  ; 
  it 
  presents 
  an 
  uneven 
  eroded 
  

   surface 
  upon 
  which 
  the 
  Beaver 
  Bay 
  diabase, 
  the 
  oldest 
  of 
  the 
  

   Keweenawan 
  lavas, 
  rests; 
  the 
  Beaver 
  Bay 
  diabase 
  contains 
  numer- 
  

   ous 
  included 
  blocks 
  of 
  anorthosite 
  which 
  were 
  evidently 
  picked 
  

   up 
  by 
  the 
  lava 
  as 
  it 
  flowed 
  over 
  the 
  surface 
  of 
  the 
  bare 
  anortho- 
  

   site, 
  or 
  which 
  were 
  detached 
  from 
  the 
  walls 
  of 
  the 
  vent 
  from 
  

   which 
  the 
  lava 
  came 
  to 
  the 
  surface 
  ; 
  the 
  resurrected 
  surface 
  of 
  

   the 
  anorthosite 
  exposed 
  by 
  the 
  removal 
  of 
  the 
  lavas 
  has 
  the 
  same 
  

   hummocky 
  uneven 
  character 
  as 
  that 
  which 
  characterizes 
  the 
  pre- 
  

   Animikie 
  surface 
  of 
  the 
  Archaean 
  generally 
  in 
  the 
  Lake 
  Superior 
  

   region 
  ; 
  the 
  anorthosite 
  has 
  a 
  well-known 
  equivalent 
  in 
  the 
  Norian 
  

   of 
  Canada. 
  These 
  considerations 
  render 
  very 
  questionable 
  the 
  

   correlation 
  of 
  the 
  Carltonian 
  anorthosite 
  with 
  the 
  Duluth 
  gabbro, 
  

   and 
  support 
  the 
  view 
  that 
  it 
  is 
  a 
  distinct 
  pre-Keweenawan 
  forma- 
  

   tion. 
  

  

  The 
  chapters 
  on 
  the 
  counties 
  in 
  which 
  the 
  phenomena 
  of 
  the 
  

   Pleistocene 
  preponderate, 
  written 
  by 
  Todd 
  and 
  Upham, 
  and 
  the 
  

   incidental 
  references 
  to 
  the 
  same 
  phenomena 
  by 
  Grant 
  and 
  Win- 
  

   chell, 
  are 
  important 
  contributions 
  to 
  the 
  subject, 
  but 
  here, 
  again 
  

   a 
  coherent 
  general 
  discussion 
  of 
  these 
  features, 
  such 
  as 
  might 
  be 
  

   expected 
  in 
  a 
  final 
  report, 
  would 
  have 
  greatly 
  enhanced 
  the 
  value 
  

   of 
  the 
  volume. 
  The 
  occasional 
  summary 
  statements 
  by 
  Todd 
  and 
  

   Grant 
  are 
  to 
  be 
  commended 
  as 
  efforts 
  in 
  this 
  direction. 
  The 
  

   characters 
  of 
  the 
  drift 
  and 
  its 
  modifications, 
  its 
  special 
  features 
  

   such 
  as 
  kames 
  and 
  pitted 
  plains, 
  the 
  distribution 
  of 
  moraines, 
  these 
  

   are 
  all 
  described 
  in 
  more 
  or 
  less 
  detail 
  ; 
  and 
  the 
  survey 
  has 
  placed 
  

   students 
  of 
  the 
  Pleistocene 
  under 
  obligations 
  for 
  its 
  painstaking 
  

   efforts 
  to 
  secure 
  local 
  information 
  on 
  these 
  matters. 
  The 
  limits 
  

   and 
  shore 
  features 
  of 
  Lake 
  Agassiz 
  are 
  discussed 
  especially 
  by 
  

   Todd 
  and 
  Grant, 
  the 
  shore 
  features 
  of 
  Lake 
  Warren 
  by 
  Grant, 
  

   and 
  the 
  early 
  outlet 
  of 
  Lake 
  Superior 
  as 
  well 
  as 
  certain 
  minor 
  

   post-Glacial 
  lakes 
  by 
  Upham. 
  In 
  most 
  of 
  the 
  chapters 
  there 
  is 
  a 
  

   statement 
  of 
  the 
  local 
  features 
  of 
  economic 
  interest; 
  and 
  the 
  final 
  

   chapter 
  by 
  H. 
  V. 
  Winchell 
  on 
  the 
  iron 
  industry 
  is 
  a 
  valuable 
  

   contribution 
  to 
  our 
  knowledge 
  of 
  the 
  great 
  iron 
  resources 
  of 
  the 
  

  

  State. 
  ANDREW 
  C. 
  LAWSON. 
  

  

  