﻿628 
  Forty- 
  seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  lowing 
  paper. 
  His 
  expenses 
  were 
  in 
  part 
  borne 
  by 
  our 
  

   appropriation, 
  but 
  chiefly 
  by 
  himself, 
  and 
  the 
  writer 
  acknowl- 
  

   edges 
  gladly 
  the 
  valuable 
  aid 
  thus 
  rendered. 
  

  

  The 
  general 
  plan 
  of 
  the 
  work 
  has 
  been 
  to 
  traverse 
  every 
  

   highway 
  affording 
  information 
  and 
  so 
  far 
  as 
  possible 
  to 
  record 
  

   the 
  rocks 
  and 
  gather 
  specimens 
  from 
  the 
  accessible 
  mountains 
  as 
  

   well. 
  The 
  numbers 
  on 
  the 
  maps 
  indicate 
  the 
  places 
  where 
  out- 
  

   crops 
  are 
  met 
  and 
  the 
  location 
  of 
  the 
  specimens 
  which 
  were 
  col- 
  

   lected 
  and 
  brought 
  back 
  for 
  study. 
  They 
  show 
  at 
  a 
  glance 
  the 
  

   proportionate 
  part 
  of 
  the 
  territory 
  that 
  has 
  been 
  actually 
  seen 
  

   in 
  the 
  field. 
  Aside 
  from 
  the 
  difficulties 
  inherent 
  in 
  the 
  geological 
  

   problem 
  itself, 
  it 
  is 
  to 
  be 
  borne 
  in 
  mind 
  that 
  the 
  country 
  back 
  

   from 
  Lake 
  Champlain 
  is 
  mountainous 
  and 
  in 
  most 
  places 
  covered 
  

   with 
  a 
  dense 
  second 
  growth 
  of 
  woods 
  which 
  mask 
  the 
  outcrops 
  

   even 
  when 
  such 
  occur. 
  One 
  may 
  tramp 
  for 
  miles 
  in 
  the 
  thick 
  

   undergrowth 
  without 
  meeting 
  a 
  ledge. 
  In 
  addition 
  to 
  this 
  the 
  

   region 
  is 
  covered 
  in 
  many 
  districts 
  with 
  glacial 
  deposits 
  which 
  

   hide 
  the 
  rocks. 
  

  

  So 
  far 
  as 
  possible 
  we 
  have 
  endeavored 
  to 
  follow 
  up 
  the 
  parties 
  

   of 
  the 
  United 
  States 
  Geological 
  Survey, 
  who 
  are 
  making 
  a 
  

   topographical 
  map 
  of 
  the 
  region, 
  and 
  while 
  in 
  several 
  towns 
  we 
  

   have 
  been 
  forced 
  to 
  rely 
  on 
  the 
  county 
  atlas 
  for 
  maps, 
  in 
  others 
  

   we 
  have 
  based 
  the 
  outlines 
  on 
  the 
  advance 
  sheets, 
  which 
  have 
  

   been 
  most 
  kindly 
  furnished 
  by 
  Mr. 
  H. 
  M. 
  Wilson, 
  to 
  whom, 
  and 
  

   to 
  Mr. 
  E. 
  0. 
  Barnard, 
  of 
  the 
  United 
  States 
  Survey, 
  acknowledg- 
  

   ments 
  are 
  here 
  made. 
  Topographical 
  maps 
  are 
  an 
  indispensable 
  

   aid 
  in 
  indicating, 
  the 
  character 
  of 
  the 
  country 
  and 
  many 
  of 
  its 
  

   important 
  geological 
  features. 
  

  

  The 
  problems 
  involved 
  in 
  unraveling 
  the 
  stratigraphical 
  rela- 
  

   tions 
  are 
  obscure 
  ones, 
  and 
  about 
  them 
  one 
  could 
  not 
  well 
  speak 
  

   finally 
  until 
  a 
  greater 
  extent 
  of 
  territory 
  has 
  been 
  covered. 
  But 
  

   in 
  the 
  Archaean 
  rocks 
  the 
  several 
  different 
  ones 
  distinguished 
  on 
  

   the 
  maps 
  stand 
  out 
  in 
  quite 
  strong 
  contrast 
  and 
  in 
  typical 
  instan- 
  

   ces 
  are 
  readily 
  recognized. 
  There 
  are, 
  however, 
  intermediate 
  

   forms 
  that 
  are 
  very 
  puzzling. 
  Thus, 
  the 
  massive 
  labradorite 
  

   rocks 
  of 
  the 
  Norian 
  series 
  of 
  Hunt, 
  are 
  very 
  evident 
  when 
  they 
  

   furnish 
  either 
  the 
  rich 
  feldspathic 
  varieties 
  (anorthosites) 
  or 
  the 
  

   dark 
  gabbros; 
  but 
  both 
  these 
  shade 
  into 
  gneisses, 
  with 
  horn- 
  

   blende, 
  pyroxene 
  and 
  quartz, 
  so 
  that 
  when 
  one 
  meets 
  a 
  rather 
  

  

  