﻿42 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Port 
  Leyden 
  it 
  lies 
  at 
  900 
  feet 
  above 
  sea 
  level. 
  The 
  distance 
  is 
  33 
  

   miles 
  and 
  the 
  difference 
  in 
  elevation 
  2400 
  feet 
  which 
  shows 
  a 
  slope 
  

   of 
  over 
  J2 
  feet 
  per 
  mile 
  southward. 
  

  

  According 
  to 
  Orton/ 
  the 
  Central 
  Square 
  (Oswego 
  co.) 
  well 
  shows 
  

   Precambric 
  at 
  2015 
  feet 
  below 
  sea 
  level, 
  while 
  at 
  Port 
  Leyden 
  its 
  

   altitude 
  is 
  900 
  feet. 
  This 
  shows 
  a 
  drop 
  of 
  2915 
  feet 
  in 
  passing 
  46 
  

   miles 
  southwestward 
  or 
  a 
  slope 
  of 
  over 
  63 
  feet 
  per 
  mile 
  toward 
  the 
  

   southwest. 
  

  

  In 
  a 
  deep 
  well 
  at 
  Pulaski 
  the 
  Precambric 
  was 
  struck 
  at 
  1048 
  feet 
  

   below 
  sea 
  level, 
  according 
  to 
  Orton.^ 
  Its 
  altitude 
  at 
  Port 
  Leyden 
  is 
  

   900 
  feet, 
  which 
  indicates 
  a 
  drop 
  of 
  1948 
  feet 
  in 
  a 
  distance 
  of 
  38 
  

   miles 
  or 
  a 
  slope 
  of 
  over 
  51 
  feet 
  per 
  mile 
  toward 
  the 
  west. 
  

  

  These 
  results 
  show 
  that 
  the 
  Precambric 
  slope 
  under 
  the 
  Paleozoics 
  

   is 
  somewhat 
  greater 
  southward 
  than 
  westward 
  and 
  that 
  the 
  general 
  

   southwestward 
  slope 
  is 
  clearly 
  less 
  than 
  it 
  is 
  in 
  the 
  Little 
  Falls 
  and 
  

   the 
  Remsen 
  districts. 
  Also 
  the 
  slope 
  under 
  the 
  Paleozoics 
  is 
  greater 
  

   than 
  where 
  no 
  sedimentaries 
  now 
  cover, 
  which 
  is 
  always 
  true 
  along 
  

   the 
  southwestern 
  border 
  of 
  the 
  Adirondacks. 
  This 
  is 
  what 
  would 
  

   be 
  expected 
  because 
  the 
  general 
  surface 
  over 
  the 
  Precambric 
  area 
  

   has 
  been 
  reduced 
  by 
  erosion 
  since 
  the 
  removal 
  of 
  the 
  sediments. 
  

   By 
  referring 
  to 
  the 
  above 
  figures 
  we 
  find 
  that 
  if 
  we 
  consider 
  a 
  due 
  

   east-west 
  line 
  through 
  the 
  Port 
  Leyden 
  district, 
  the 
  Precambric 
  

   slope 
  under 
  the 
  Paleozoics 
  is 
  actually 
  a 
  little 
  less 
  than 
  it 
  is 
  east 
  of 
  

   them. 
  This 
  certainly 
  means 
  that 
  the 
  slope 
  of 
  the 
  Precambric 
  sur- 
  

   face, 
  before 
  the 
  removal 
  of 
  the 
  sediments, 
  must 
  have 
  been 
  steeper 
  

   eastward 
  from 
  Port 
  Leyden 
  than 
  westward, 
  and 
  that 
  it 
  is 
  still 
  

   steeper 
  in 
  spite 
  of 
  the 
  later 
  erosion. 
  

  

  Slope 
  of 
  the 
  Precambric 
  surface 
  during 
  Paleozoic 
  deposition 
  

  

  It 
  is 
  possible 
  to 
  get 
  some 
  idea 
  regarding 
  the 
  slope 
  of 
  the 
  surface 
  

   upon 
  which 
  the 
  older 
  Paleozoics 
  were 
  being 
  deposited 
  by 
  comparing 
  

   the 
  thickness 
  of 
  these 
  formations 
  with 
  the 
  same 
  ones 
  to 
  the 
  west 
  and 
  

   southwest 
  in 
  Oswego 
  county. 
  This 
  comparison 
  may 
  be 
  most 
  satis- 
  

   factorily 
  made 
  by 
  considering 
  together 
  all 
  of 
  the 
  deposits 
  from 
  the 
  

   top 
  of 
  the 
  Trenton 
  to 
  the 
  Precambric, 
  because 
  in 
  the 
  well 
  sections 
  

   the 
  different 
  formations 
  are 
  not 
  clearly 
  distinguished. 
  

  

  In 
  the 
  well 
  at 
  Pulaski^ 
  the 
  thickness 
  of 
  the 
  strata 
  from 
  the 
  top 
  of 
  

   the 
  Trenton 
  to 
  the 
  Precambric 
  is 
  900 
  feet, 
  while 
  the 
  corresponding 
  

  

  1 
  loc. 
  cit. 
  p. 
  455. 
  

  

  2 
  loc. 
  cit. 
  p. 
  489. 
  

  

  3 
  loc. 
  cit. 
  p. 
  489. 
  

  

  