﻿GEOLOGY 
  OF 
  THOUSAND 
  ISLANDS 
  REGION 
  153 
  

  

  plucking 
  on 
  the 
  limestone 
  ledges 
  ; 
  which 
  previously 
  had 
  been 
  at- 
  

   tacked 
  from 
  the 
  northward. 
  

  

  The 
  massing 
  or 
  localization 
  of 
  the 
  drift^ 
  so 
  unlike 
  anything 
  else- 
  

   where 
  in 
  the 
  southern 
  half 
  of 
  our 
  area, 
  suggests 
  that 
  it 
  was 
  the 
  

   accumulation 
  produced 
  by 
  a 
  readvance 
  of 
  the 
  ice 
  margin, 
  and 
  was 
  

   followed 
  by 
  a 
  retreat 
  of 
  the 
  ice 
  front 
  to 
  the 
  latitude 
  of 
  Clayton, 
  

   where 
  the 
  glaciers 
  made 
  another 
  stand, 
  or 
  readvance, 
  with 
  accumula- 
  

   tion 
  of 
  another 
  belt 
  of 
  heavy 
  boulder 
  moraine 
  (or 
  boulder 
  kame) 
  in 
  

   the 
  Clayton-Lafargeville-Redwood 
  moraine. 
  

  

  Boulder 
  kames. 
  The 
  glacial 
  deposits 
  with 
  sharpest 
  relief 
  and, 
  

   outside 
  the 
  Black 
  river 
  moraine, 
  the 
  most 
  conspicuous 
  masses 
  are 
  

   the 
  detached 
  or 
  isolated 
  hills 
  of 
  boulders 
  and 
  cobbles 
  which 
  fall 
  

   in 
  this 
  class. 
  With 
  little 
  attempt 
  to 
  classify 
  the 
  drift 
  forms 
  these 
  

   would 
  be 
  called 
  bouldery 
  moraine, 
  but 
  on 
  account 
  of 
  the 
  predomi- 
  

   nance 
  of 
  water-worn 
  materials 
  in 
  the 
  hills 
  and 
  on 
  their 
  flanks, 
  and 
  

   their 
  isolation, 
  it 
  is 
  thought 
  best 
  to 
  distinguish 
  them 
  as 
  a 
  form 
  

   between 
  true 
  moraines 
  and 
  typical 
  kames. 
  They 
  stand 
  out 
  isolated, 
  

   apart 
  from 
  any 
  line 
  or 
  ridge 
  of 
  moraine, 
  being 
  the 
  most 
  striking 
  

   hills 
  of 
  their 
  neighborhoods. 
  One 
  known 
  as 
  the 
  " 
  Hogsback 
  " 
  lies 
  

   1 
  1/2 
  miles 
  northeast 
  of 
  St 
  Lawrence 
  and 
  4 
  miles 
  southwest 
  of 
  Clay- 
  

   ton 
  and 
  is 
  over 
  100 
  feet 
  high. 
  Four 
  smaller 
  but 
  conspicuous 
  coni- 
  

   cal 
  hills 
  lie 
  in 
  chain, 
  in 
  the 
  line 
  of 
  ice 
  flow, 
  in 
  esker-kame 
  fashion, 
  

   forming 
  the 
  river 
  front 
  of 
  Prospect 
  Park, 
  west 
  of 
  Clayton. 
  These 
  

   are 
  shown 
  in 
  plate 
  46. 
  The 
  same 
  map 
  shows 
  the 
  striking 
  group 
  

   of 
  cobble 
  hills 
  2 
  miles 
  north 
  of 
  Lafargeville, 
  having 
  an 
  east-west 
  

   distribution 
  and 
  somewhat 
  morainic 
  aspect, 
  which 
  have 
  supplied 
  the 
  

   materials 
  for 
  the 
  best 
  display 
  of 
  Gilbert 
  bars 
  in 
  the 
  entire 
  area 
  

   [pi. 
  49-53]. 
  On 
  the 
  t(^gQ 
  of 
  this 
  map 
  and 
  reaching 
  over 
  on 
  the 
  

   Alexandria 
  sheet 
  [pi. 
  47] 
  is 
  another 
  prominent 
  hill, 
  called 
  Pine 
  

   Grove 
  hill, 
  5 
  miles 
  northeast 
  of 
  Lafargeville 
  and 
  nearly 
  4 
  miles 
  

   southwest 
  of 
  Plessis. 
  Xqyy 
  heavy 
  cobble 
  bars 
  of 
  Gilbert 
  waters 
  

   are 
  thrown 
  north 
  and 
  south 
  from 
  this 
  hill, 
  shown 
  in 
  plates 
  45, 
  46. 
  

   A 
  pit 
  for 
  gravel 
  has 
  been 
  dug 
  on 
  the 
  summit 
  of 
  the 
  hill. 
  Yet 
  an- 
  

   other 
  hill 
  of 
  this 
  kind 
  is 
  shown 
  on 
  plate 
  47, 
  ^ 
  mile 
  northwest 
  of 
  

   Redwood. 
  There 
  is 
  a 
  chain 
  of 
  similar 
  hills 
  all 
  along 
  the 
  north 
  side 
  

   of 
  Grindstone 
  island. 
  

  

  From 
  the 
  large 
  amount 
  of 
  rounded 
  or 
  water-transported 
  materials 
  

   in 
  these 
  hills, 
  their 
  isolation 
  and 
  their 
  form 
  and 
  alinement, 
  it 
  ap- 
  

   pears 
  that 
  they 
  were 
  built, 
  at 
  least 
  in 
  larger 
  part, 
  by 
  torrential 
  

   streams. 
  And 
  as 
  all 
  the 
  area 
  was 
  buried 
  under 
  deep 
  waters 
  of 
  

   Lake 
  Iroquois 
  during 
  the 
  ice 
  waning 
  it 
  would 
  appear 
  that 
  the 
  

   streams 
  must 
  have 
  been 
  surficial 
  to 
  the 
  ice 
  sheet 
  and 
  have 
  poured 
  

  

  