﻿GEOLOGY 
  OF 
  THE 
  PORT 
  LEYDEN 
  QUADRANGLE 
  4I 
  

  

  Near 
  Partridgeville 
  the 
  Precambric 
  lies 
  at 
  about 
  1300 
  feet 
  above 
  

   the 
  sea 
  level, 
  while 
  at 
  Hawkinsville 
  (Boonville 
  sheet), 
  16 
  miles 
  

   southward, 
  it 
  lies 
  at 
  1060 
  feet. 
  The 
  difference 
  in 
  elevation 
  is 
  240 
  

   feet 
  or 
  the 
  slope 
  per 
  mile 
  southward 
  is 
  15 
  feet 
  between 
  these 
  places. 
  

  

  One 
  mile 
  south 
  of 
  Donnattsburg 
  the 
  Precambric 
  is 
  at 
  1020 
  feet, 
  

   while 
  at 
  Port 
  Leyden, 
  10^ 
  miles 
  southward, 
  its 
  elevation 
  is 
  900' 
  

   feet. 
  The 
  difference 
  in 
  elevation 
  of 
  120 
  feet 
  shows 
  a 
  southward 
  

   slope 
  of 
  over 
  11 
  feet 
  per 
  mile 
  in 
  this 
  direction. 
  

  

  The 
  Precambric 
  near 
  Partridgeville 
  is 
  at 
  1300 
  feet, 
  while 
  just 
  west 
  

   of 
  Glenfield, 
  7^4 
  miles 
  westward, 
  it 
  lies 
  at 
  840 
  feet. 
  Thus 
  we 
  get 
  a 
  

   difference 
  in 
  elevation 
  of 
  460 
  feet 
  or 
  a 
  slope 
  per 
  mile 
  of 
  61 
  feer 
  

   toward 
  the 
  west. 
  In 
  a 
  similar 
  way 
  we 
  may 
  find 
  a 
  slope, 
  between 
  

   Lyons 
  Falls 
  and 
  a 
  point 
  east 
  of 
  Fowlersville, 
  of 
  67 
  feet 
  per 
  mile 
  

   westward. 
  

  

  In 
  the 
  vicinity 
  of 
  Woodhull 
  lake, 
  at 
  the 
  western 
  edge 
  of 
  the 
  Old 
  

   Forge 
  sheet, 
  the 
  Precambric 
  elevation 
  is 
  2000 
  feet 
  while 
  at 
  Port 
  

   Leyden, 
  17 
  miles 
  westw^ard, 
  it 
  is 
  900 
  feet. 
  The 
  difference 
  in 
  alti- 
  

   tude 
  is 
  Tioo 
  feet 
  which 
  means 
  a 
  westward 
  slope 
  of 
  nearly 
  65 
  feet 
  

   per 
  mile. 
  

  

  These 
  comparisons 
  clearly 
  demonstrate 
  that 
  the 
  Precambric 
  sur- 
  

   face 
  now 
  slopes 
  both 
  southward 
  and 
  westward, 
  but 
  that 
  the 
  west- 
  

   ward 
  slope 
  is 
  much 
  steeper. 
  The 
  writer 
  has 
  compared 
  Precambric 
  

   altitudes 
  at 
  many 
  points 
  over 
  the 
  Port 
  Leyden, 
  Remsen, 
  Wilmurt 
  

   and 
  Little 
  Falls 
  quadrangles. 
  The 
  conclusion 
  reached 
  is 
  that 
  the 
  

   exposed 
  Precambric 
  surface 
  along 
  the 
  southwestern 
  Adirondack? 
  

   slopes 
  both 
  westward 
  and 
  southward 
  ; 
  that 
  the 
  slope 
  toward 
  the 
  west 
  

   is 
  steeper 
  (being 
  from 
  60 
  to 
  100 
  feet) 
  than 
  the 
  slope 
  toward 
  the 
  

   south 
  (being 
  from 
  11 
  to 
  50 
  feet) 
  ; 
  and 
  that 
  the 
  general 
  southwest- 
  

   ward 
  slope 
  is 
  greater 
  in 
  the 
  Little 
  Falls 
  than 
  in 
  the 
  Port 
  Leyden 
  

   region. 
  

  

  Slope 
  of 
  the 
  Precambric 
  surface 
  where 
  Paleozoics 
  now 
  cover 
  

  

  Having 
  acquired 
  some 
  idea 
  regarding 
  the 
  slope 
  of 
  the 
  exposed 
  

   Precambric 
  surface 
  it 
  will 
  now 
  be 
  of 
  interest 
  to 
  determine 
  the 
  slope 
  

   of 
  the 
  Precambric 
  surface 
  where 
  Paleozoics 
  now 
  cover. 
  This 
  may 
  

   be 
  done 
  by 
  comparing 
  altitudes 
  of 
  the 
  Precambric 
  within 
  the 
  Port 
  

   Leyden 
  quadrangle 
  with 
  the 
  Precambric 
  altitudes 
  as 
  found 
  in 
  cer- 
  

   tain 
  deep 
  wells 
  to 
  the 
  south, 
  southwest 
  and 
  west. 
  

  

  In 
  the 
  Campbell 
  well 
  3 
  miles 
  west 
  of 
  Utica, 
  according 
  to 
  Prosser,^ 
  

   the 
  Precambric 
  was 
  struck 
  at 
  1500 
  feet 
  below 
  sea 
  level, 
  while 
  at 
  

  

  ^ 
  Gcol. 
  Soc. 
  Am. 
  Bui. 
  1893. 
  4:101. 
  

  

  