﻿GEOLOGY 
  OF 
  THE 
  NORTH 
  CREEK 
  QUADRANGLE 
  6/ 
  

  

  against 
  the 
  much 
  higher 
  mountains 
  which 
  are 
  arranged 
  along 
  the 
  

   eastern 
  side 
  of 
  the 
  adjoining 
  Thirteenth 
  Lake 
  sheet. 
  

  

  Some 
  of 
  the 
  striae 
  are 
  so 
  situated 
  in 
  valleys 
  as 
  to 
  suggest 
  that, 
  

   locally 
  at 
  least, 
  the 
  ice 
  currents 
  followed 
  the 
  valleys, 
  but 
  many 
  

   others 
  are 
  situated 
  wholly 
  without 
  reference 
  to 
  the 
  topography, 
  

   Among 
  the 
  best 
  examples 
  of 
  striae 
  which 
  are 
  significant 
  as 
  proving- 
  

   that 
  the 
  general 
  ice 
  movement 
  was 
  irrespective 
  of 
  even 
  the 
  major 
  

   topographic 
  features 
  are 
  the 
  following: 
  just 
  north 
  of 
  Mud 
  pond 
  

   and 
  immediately 
  south 
  of 
  the 
  Huckleberry-Crane-Little 
  mountains 
  

   masses, 
  thus 
  showing 
  the 
  retention 
  of 
  the 
  southward 
  course 
  ins 
  

   spite 
  of 
  those 
  mountains 
  ; 
  immediately 
  under 
  the 
  steep 
  fault 
  scarp* 
  

   on 
  the 
  east 
  side 
  of 
  Loon 
  lake 
  ; 
  at 
  the 
  north 
  bases 
  of 
  Pine 
  and 
  Gage, 
  

   mountains, 
  showing 
  that 
  the 
  ice 
  current 
  headed 
  straight 
  for 
  t&ase- 
  

   high 
  mountains 
  ; 
  and 
  on 
  the 
  hilltop 
  just 
  northwest 
  of 
  Johnsburgf; 
  

   where 
  the 
  ice 
  left 
  its 
  record 
  after 
  having 
  plowed 
  diagonally 
  up> 
  

   the 
  hill 
  for 
  an 
  altitude 
  of 
  several 
  hundred 
  feet 
  instead 
  of 
  following' 
  

   the 
  valley. 
  

  

  The 
  great 
  depth 
  of 
  ice 
  over 
  the 
  region 
  is 
  proved 
  by 
  the 
  frequent 
  

   occurrence 
  of 
  drift 
  boulders 
  even 
  on 
  the 
  high 
  mountains, 
  the 
  high 
  

   altitudes 
  of 
  some 
  of 
  the 
  striae, 
  and 
  the 
  glacial 
  lake 
  on 
  Crane 
  moun- 
  

   tain. 
  Some 
  of 
  the 
  striae 
  at 
  considerable 
  altitudes 
  are 
  as 
  follows 
  z 
  

   north 
  of 
  Mud 
  pond 
  (southwest 
  corner) 
  at 
  nearly 
  2000 
  feet; 
  2? 
  

   miles 
  east 
  of 
  Cherry 
  ridge 
  at 
  from 
  1500 
  to 
  1600 
  feet; 
  west 
  base 
  of 
  

   No. 
  9 
  mountain 
  at 
  1600 
  feet; 
  2^/2 
  miles 
  southwest 
  of 
  Johnsburg-; 
  

   at 
  1550 
  feet; 
  on 
  the 
  side 
  of 
  Stockton 
  mountain 
  at 
  over 
  1500 
  feetp 
  

   and 
  one-half 
  of 
  a 
  mile 
  northwest 
  of 
  Johnsburg 
  on 
  a 
  hilltop 
  at 
  1480 
  

   feet. 
  On 
  this 
  basis, 
  granting 
  a 
  fairly 
  level 
  ice 
  surface, 
  the 
  depth 
  

   of 
  ice 
  must 
  have 
  been 
  at 
  least 
  1000 
  feet 
  or 
  the 
  difference 
  between 
  

   these 
  highest 
  striae 
  and 
  the 
  Hudson 
  river 
  to 
  the 
  east. 
  However, 
  

   the 
  presence 
  of 
  the 
  glacial 
  lake 
  with 
  drift 
  dam 
  well 
  up 
  on 
  Crane 
  

   mountain, 
  and 
  at 
  an 
  altitude 
  of 
  2620 
  feet, 
  shows 
  that 
  the 
  ice 
  was 
  

   deep 
  enough 
  to 
  cover 
  the 
  mountain 
  that 
  high 
  up 
  at 
  least. 
  Accord- 
  

   ing 
  to 
  this 
  the 
  ice 
  must 
  have 
  been 
  at 
  least 
  1500 
  feet 
  deep 
  in 
  the- 
  

   valley 
  just 
  north 
  of 
  Thurman 
  and 
  fully 
  2000 
  feet 
  deep 
  in 
  the 
  

   valley 
  of 
  the 
  Hudson 
  river. 
  

  

  ICE 
  EROSION 
  

  

  To 
  say 
  the 
  least, 
  ice 
  erosion 
  was 
  very 
  effective 
  in 
  the 
  rerrrova? 
  

   of 
  nearly 
  all 
  preglacial 
  soils, 
  decomposed 
  rock, 
  and 
  loose 
  joint 
  

   blocks. 
  The 
  mountains 
  were 
  swept 
  clean 
  of 
  such 
  materials 
  and 
  left 
  

   standing 
  as 
  more 
  or 
  less 
  rounded 
  off 
  bare 
  rock 
  ledges, 
  while 
  during 
  

  

  3 
  

  

  