﻿1 
  8 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  the 
  Adirondack's 
  along 
  the 
  International 
  boundary 
  to 
  Lake 
  Cham- 
  

   plain. 
  The 
  customary 
  classification 
  of 
  glacial 
  deposits 
  for 
  the 
  

   purpose 
  of 
  geologic 
  mapping 
  breaks 
  down 
  in 
  this 
  area 
  by 
  reason 
  

   of 
  the 
  modification 
  of 
  the 
  deposits 
  through 
  action 
  of 
  sea 
  waves 
  and 
  

   currents. 
  The 
  problem 
  of 
  how 
  best 
  to 
  map 
  these 
  modified 
  glacial 
  

   deposits 
  has 
  perhaps 
  not 
  yet 
  been 
  satisfactorily 
  solved. 
  The 
  prob- 
  

   lem 
  is 
  a 
  particularly 
  difficult 
  one 
  by 
  reason 
  of 
  the 
  varying 
  degree 
  

   of 
  alteration 
  and 
  rearrangement 
  of 
  the 
  original 
  accumulations. 
  

   Some 
  parts 
  of 
  the 
  area 
  display 
  a 
  typical 
  glacial 
  topography 
  and 
  

   underlying 
  structure 
  of 
  the 
  materials; 
  yet 
  other 
  districts 
  show 
  the 
  

   glacial 
  deposits 
  entirely 
  recomposed 
  in 
  beaches, 
  bars, 
  and 
  offshore 
  

   sediments. 
  These 
  features 
  are 
  not 
  always 
  clear; 
  there 
  are 
  large 
  

   tracts 
  in 
  which 
  no 
  distinctive 
  surface 
  characters 
  exist 
  and 
  in 
  which 
  

   the 
  deposits 
  can 
  only 
  be 
  discriminated 
  on 
  such 
  broad 
  groupings 
  as 
  

   stratified, 
  gravelly, 
  sandy 
  or 
  clayey. 
  This 
  results 
  in 
  the 
  necessity 
  

   of 
  coloring 
  large 
  areas 
  as 
  undifferentiated 
  glacial 
  and 
  marine 
  or 
  

   glacio-marine 
  gravels 
  and 
  sands. 
  

  

  On 
  the 
  Rouse 
  Point 
  quadrangle 
  there 
  is 
  a 
  marked 
  belt 
  of 
  sandy 
  

   beach 
  deposits 
  about 
  the 
  hills 
  at 
  levels 
  between 
  180 
  and 
  220 
  feet 
  

   above 
  sea 
  level. 
  Along 
  the 
  northern 
  border 
  of 
  the 
  area 
  in 
  the 
  vicin- 
  

   ity 
  of 
  Champlain 
  village, 
  pocket 
  beaches 
  occur 
  at 
  lower 
  levels. 
  

   Marine 
  shells 
  have 
  been 
  found 
  in 
  sufficient 
  abundance 
  to 
  give 
  some 
  

   idea 
  of 
  the 
  fauna. 
  There 
  is 
  a 
  noticeable 
  abundance 
  of 
  M 
  y 
  a 
  

   arenaria 
  at 
  these 
  lower 
  levels, 
  but 
  it 
  is 
  absent 
  at 
  the 
  higher 
  

   stands 
  of 
  the 
  sea. 
  Either 
  this 
  mollusk 
  reached 
  the 
  area 
  relatively 
  

   late 
  or 
  lived 
  only 
  in 
  the 
  deeper 
  offshore 
  stations. 
  Owing 
  to 
  its 
  

   abundance 
  in 
  shallow 
  surface 
  deposits 
  I 
  am 
  inclined 
  to 
  the 
  view 
  that 
  

   it 
  migrated 
  into 
  the 
  Champlain 
  area 
  much 
  later 
  than 
  S 
  a 
  x 
  i 
  c 
  a 
  v 
  a 
  

   r 
  u 
  g 
  o 
  s 
  a 
  and 
  Macoma 
  greenlandica. 
  If 
  this 
  be 
  true 
  it 
  

   may 
  be 
  possible 
  to 
  differentiate 
  locally 
  these 
  life 
  zones. 
  M 
  y 
  t 
  i 
  1 
  u 
  s 
  

   e 
  d 
  u 
  1 
  i 
  s 
  also 
  appears 
  in 
  abundance 
  and 
  in 
  an 
  excellent 
  state 
  of 
  

   preservation 
  at 
  these 
  lower 
  levels, 
  as 
  on 
  the 
  Isle 
  la 
  Motte. 
  

  

  The 
  field 
  work 
  indicates 
  pretty 
  clearly 
  that 
  a 
  morainal 
  belt 
  extends 
  

   southeastward 
  across 
  the 
  Mooers 
  area 
  towards 
  Chazy, 
  indicating 
  a 
  

   protrusion 
  of 
  the 
  ice 
  front 
  into 
  the 
  Champlain 
  embayment 
  at 
  a 
  late 
  

   stage, 
  possibly 
  as 
  an 
  ice 
  advance 
  after 
  the 
  sea 
  once 
  got 
  into 
  the 
  

   area. 
  Unless 
  the 
  unfossiliferous 
  clays 
  about 
  East 
  Beekmantown 
  

   and 
  near 
  the 
  lake 
  shores 
  in 
  that 
  vicinity 
  and 
  around 
  Alburg 
  can 
  be 
  

   referred 
  to 
  the 
  lacustrine 
  stage, 
  no 
  deposits 
  are 
  recognized 
  which 
  

   can 
  be 
  definitely 
  referred 
  to 
  the 
  glacial 
  lake 
  waters 
  which 
  preceded 
  

   the 
  marine 
  invasion 
  in 
  this 
  field, 
  nor 
  have 
  any 
  Prewisconsin 
  drift 
  

   deposits 
  been 
  found. 
  

  

  