﻿98 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Dip 
  of 
  the 
  Paleozoic 
  rocks 
  

  

  It 
  has 
  just 
  been 
  stated 
  that 
  the 
  Paleozoic 
  rocks 
  dip 
  away 
  from 
  the 
  

   Frontenac 
  axis 
  in 
  both 
  directions, 
  and 
  it 
  is 
  desirable 
  to 
  scrutinize 
  the 
  

   matter 
  somewhat 
  more 
  closely. 
  

  

  In 
  the 
  southeastern 
  corner 
  of 
  the 
  Theresa 
  quadrangle 
  the 
  base 
  of 
  

   the 
  Leray 
  limestone 
  is 
  at 
  600 
  feet 
  altitude. 
  The 
  general 
  line 
  

   of 
  outcrop 
  of 
  the 
  formation 
  runs 
  across 
  the 
  mapped 
  area 
  in 
  a 
  west- 
  

   northwest 
  direction, 
  and 
  on 
  the 
  Cape 
  Vincent 
  sheet 
  passes 
  beneath 
  

   the 
  river 
  level 
  247 
  feet. 
  This 
  is 
  a 
  drop 
  in 
  altitude 
  of 
  353 
  feet 
  in 
  27 
  

   miles, 
  about 
  13 
  feet 
  to 
  the 
  mile, 
  in 
  this 
  west-northwest 
  direction. 
  In 
  

   the 
  direction 
  of 
  due 
  west 
  it 
  is 
  about 
  16 
  feet 
  per 
  mile, 
  as 
  nearly 
  as 
  can 
  

   be 
  calculated. 
  Neither 
  one 
  of 
  these, 
  however, 
  gives 
  the 
  direction 
  of 
  

   true 
  dip, 
  which 
  lies 
  somewhere 
  between 
  s. 
  30° 
  w. 
  and 
  s. 
  45° 
  w. 
  At 
  

   Adams, 
  which 
  lies 
  some 
  30 
  miles 
  somewhat 
  west 
  of 
  south 
  of 
  the 
  vil- 
  

   lage 
  of 
  Theresa, 
  three 
  deep 
  wells 
  were 
  drilled 
  for 
  gas 
  some 
  years 
  

   ago, 
  and 
  the 
  records 
  of 
  these 
  wells 
  are 
  given 
  by 
  Orton.^ 
  Fairchild, 
  

   who 
  is 
  familiar 
  with 
  the 
  region, 
  has 
  also 
  supplied 
  me 
  with 
  data. 
  

   Starting 
  on 
  ground 
  whose 
  altitude 
  is 
  approximately 
  600 
  feet 
  above 
  

   sea 
  level, 
  these 
  wells 
  reached 
  the 
  Precambric 
  at 
  depths 
  of 
  915, 
  950 
  

   and 
  960 
  feet 
  respectively. 
  The 
  Precambric 
  surface 
  is 
  here 
  approxi- 
  

   mately 
  315 
  feet 
  below 
  sea 
  level, 
  while 
  at 
  Theresa 
  it 
  averages 
  about 
  

   400 
  feet 
  above 
  the 
  sea. 
  In 
  the 
  30 
  miles 
  then, 
  this 
  surface 
  drops 
  715 
  

   feet, 
  or 
  nearly 
  24 
  feet 
  to 
  the 
  mile. 
  This 
  however 
  is 
  the 
  slope 
  of 
  the 
  

   Precambric 
  surface, 
  which 
  may 
  or 
  may 
  not 
  coincide 
  with 
  the 
  dip, 
  

   and 
  in 
  all 
  probability 
  does 
  not. 
  If 
  the 
  different 
  limestones 
  could 
  be 
  

   distinguished 
  in 
  the 
  w'ell 
  records 
  the 
  data 
  would 
  be 
  at 
  hand 
  for 
  deter- 
  

   mining 
  the 
  dip, 
  but 
  this 
  is 
  unfortunately 
  not 
  the 
  case. 
  If 
  the 
  Paleozoic 
  

   rocks 
  thicken 
  in 
  that 
  direction, 
  the 
  dip 
  is 
  somewhat 
  less 
  than 
  the 
  

   above 
  figure; 
  if 
  they 
  thin 
  it 
  is 
  somew^hat 
  greater. 
  At 
  Adams 
  the 
  

   Potsdam 
  and 
  Theresa 
  formations, 
  150 
  feet 
  in 
  thickness 
  about 
  

   Theresa, 
  have 
  disappeared. 
  The 
  other 
  formations 
  are 
  present 
  how- 
  

   ever 
  and 
  are 
  unquestionably 
  thicker 
  than 
  at 
  Theresa. 
  Beginning 
  

   near 
  the 
  summit 
  of 
  the 
  Trenton, 
  the 
  drill 
  at 
  Adams 
  penetrated 
  

   through 
  900 
  feet 
  of 
  limestone 
  before 
  reaching 
  the 
  Precambric. 
  If 
  

   we 
  knew 
  the 
  thickness 
  of 
  the 
  Trenton 
  in 
  our 
  district 
  here 
  w^e 
  should 
  

   again 
  have 
  the 
  necessary 
  data, 
  but 
  all 
  the 
  upper 
  Trenton 
  lies 
  to 
  the 
  

   south 
  of 
  the 
  map 
  limits, 
  and 
  the 
  thickness 
  of 
  the 
  formation 
  has 
  never 
  

   been 
  accurately 
  measured 
  so 
  far 
  as 
  we 
  know. 
  It 
  is 
  certainly 
  as 
  much 
  

   as 
  500 
  feet 
  and 
  may 
  be 
  a 
  hundred 
  feet 
  more 
  than 
  that. 
  We 
  have 
  

   then 
  at 
  least 
  800 
  feet 
  of 
  Paleozoic 
  rocks 
  here 
  below 
  the 
  Utica, 
  and 
  

   perhaps 
  900. 
  It 
  seems 
  therefore 
  that 
  the 
  thickening 
  of 
  the 
  upper 
  

  

  IN. 
  Y. 
  State 
  Mus. 
  Bui. 
  30, 
  p. 
  457-58. 
  

  

  