﻿INTRODUCTION 
  

  

  As 
  originally 
  planned 
  the 
  field 
  work 
  for 
  1897 
  in 
  the 
  western 
  

   half 
  of 
  the 
  Adirondack 
  region 
  was 
  to 
  consist 
  of 
  two 
  distinct 
  

   parts. 
  It 
  was 
  thought 
  advisable 
  first 
  to 
  make 
  a 
  somewhat 
  de- 
  

   tailed 
  study 
  of 
  what 
  seems, 
  in 
  its 
  bearing 
  upon 
  the 
  great 
  prob- 
  

   lems 
  of 
  the 
  region, 
  to 
  be 
  a 
  critical 
  area 
  embraced 
  within 
  the 
  

   towns 
  of 
  , 
  Diana 
  and 
  Croghan, 
  Lewis 
  co. 
  and 
  Pitcairn 
  and 
  'Fine, 
  

   St 
  Lawrence 
  co. 
  

  

  After 
  the 
  completion 
  of 
  this 
  work, 
  the 
  intention 
  was 
  to 
  make 
  

   a 
  reconnoissance 
  into 
  the 
  heart 
  of 
  the 
  region 
  in 
  Herkimer 
  and 
  

   Hamilton 
  counties. 
  While 
  this 
  trip 
  was 
  planned 
  as 
  a 
  means 
  of 
  

   acquiring 
  all 
  possible 
  data 
  for 
  use 
  in 
  mapping, 
  its 
  particular 
  aim 
  

   was 
  to 
  ascertain 
  whether 
  or 
  not 
  the 
  Adirondack 
  region 
  as 
  a 
  

   whole 
  consists, 
  as 
  has 
  been 
  suggested 
  by 
  Van 
  Hise, 
  a 
  of 
  a 
  great 
  

   central 
  mass 
  or 
  core 
  of 
  gabbro, 
  surrounded 
  by 
  a 
  fringe 
  of 
  gneisses, 
  

   schists, 
  limestone, 
  etc. 
  with 
  a 
  quaquaversal 
  dip. 
  

  

  The 
  latter 
  half 
  of 
  the 
  plan, 
  thus 
  sketched, 
  was 
  carried 
  through 
  

   on 
  the 
  lines 
  originally 
  laid 
  down 
  and 
  with 
  satisfactory 
  results. 
  

   But 
  the 
  Diana-Pitcairn 
  region 
  proved 
  to 
  be 
  so 
  complex 
  that 
  it 
  

   was 
  found 
  impossible 
  to 
  solve 
  many 
  of 
  the 
  problems 
  afforded 
  in 
  

   the 
  time 
  available 
  for 
  the 
  purpose 
  and 
  with 
  the 
  very 
  imperfect 
  

   maps 
  at 
  hand, 
  and 
  the 
  work 
  was 
  finally 
  dropped, 
  to 
  be 
  taken 
  up 
  

   again 
  it 
  is 
  hoped 
  in 
  a 
  short 
  time. 
  Nevertheless 
  as 
  some 
  valuable 
  

   data 
  were 
  procured, 
  in 
  spite 
  of 
  the 
  unfinished 
  state 
  of 
  the 
  inves- 
  

   tigation, 
  the 
  writer 
  will 
  record 
  them 
  in 
  the 
  succeeding 
  pages 
  that 
  

   they 
  may 
  be 
  available 
  should 
  the 
  completion 
  of 
  the 
  work 
  for 
  any 
  

   reason 
  fall 
  to 
  others. 
  

  

  DIANA-PITCAIRN 
  AREA 
  

  

  A 
  belt 
  of 
  crystalline 
  limestone 
  crossing 
  this 
  area 
  with 
  a 
  north- 
  

   easterly 
  trend 
  divides 
  it 
  into 
  two 
  dissimilar 
  portions. 
  The 
  

   northern 
  margin 
  of 
  the 
  limestone 
  is 
  cut 
  by 
  numerous 
  intrusions, 
  

  

  a 
  Correlation 
  papers. 
  Archean 
  and 
  Algonkian, 
  Bull. 
  86, 
  U. 
  S. 
  geol. 
  surv. 
  398, 
  399, 
  413, 
  414 
  and 
  

   Principles 
  of 
  North 
  American 
  Pre-Cambian 
  geology. 
  16th 
  an. 
  rep't 
  U. 
  S. 
  geol. 
  surv., 
  p. 
  771-73. 
  

  

  