﻿GEOLOGY 
  OF 
  SARATOGA 
  SPRINGS 
  AND 
  VICINITY 
  65 
  

  

  is 
  commonly 
  elevated 
  territory, 
  the 
  Paleozoic 
  contrastingly 
  at 
  

   low 
  altitude. 
  The 
  abrupt 
  way 
  in 
  which 
  such 
  Precambric 
  ridges 
  

   as 
  those 
  of 
  French 
  and 
  Putnam 
  mountains, 
  and 
  of 
  Sugar 
  Loaf, 
  on 
  

   the 
  Glens 
  Falls 
  quadrangle, 
  break 
  off 
  at 
  the 
  south, 
  with 
  an 
  abrupt 
  

   drop 
  in 
  level 
  of 
  from 
  500 
  to 
  800 
  feet, 
  would 
  seem 
  of 
  necessity 
  to 
  

   imply 
  cross 
  faulting 
  in 
  the 
  fault 
  slices 
  concerned. 
  

  

  On 
  the 
  Saratoga 
  quadrangle 
  the 
  evidence 
  for 
  cross 
  breaks 
  at 
  

   the 
  contact 
  between 
  the 
  Amsterdam 
  limestone 
  and 
  the 
  over- 
  

   lying 
  Canajoharie 
  shale 
  seems 
  quite 
  conclusive. 
  The 
  Amsterdam 
  

   dips 
  to 
  the 
  south 
  are 
  always 
  higher 
  than 
  those 
  of 
  the 
  Little 
  Falls 
  

   dolomite, 
  showing 
  downfolding 
  or 
  downdragging 
  in 
  that 
  direction, 
  

   and 
  in 
  the 
  shales 
  the 
  dips 
  are 
  even 
  higher 
  for 
  a 
  time, 
  so 
  that 
  even 
  

   close 
  to 
  the 
  Amsterdam 
  border 
  the 
  thickness 
  of 
  shale 
  over 
  the 
  

   limestone 
  is 
  considerable. 
  Exposures 
  do 
  not 
  suffice 
  to 
  determine 
  

   whether 
  we 
  are 
  dealing 
  with 
  monoclinal 
  folding 
  or 
  with 
  faulting; 
  

   but 
  since 
  the 
  former 
  could 
  be 
  considered 
  merely 
  an 
  initial 
  phase 
  

   of 
  the 
  latter, 
  either 
  one 
  would 
  indicate 
  the 
  horizon 
  as 
  a 
  likely 
  one 
  

   for 
  cross 
  breaks. 
  

  

  Joints. 
  Our 
  readings 
  on 
  joint 
  directions 
  on 
  the 
  Saratoga 
  quad- 
  

   rangle 
  are 
  not 
  sufficiently 
  numerous 
  to 
  make 
  it 
  worth 
  while 
  to 
  plot 
  

   them. 
  The 
  Precambric 
  rocks 
  cover 
  but 
  a 
  small 
  portion 
  of 
  the 
  

   quadrangle. 
  They 
  are 
  as 
  usual 
  much 
  jointed 
  nearly 
  everywhere 
  

   and 
  appear 
  to 
  be 
  referable 
  to 
  four 
  sets, 
  a 
  north-south, 
  an 
  east- 
  

   west, 
  a 
  northeast 
  and 
  a 
  northwest 
  set. 
  But 
  they 
  do 
  not 
  hold 
  their 
  

   direction 
  true, 
  curving 
  through 
  considerable 
  arcs. 
  In 
  the 
  Gren- 
  

   ville 
  strike 
  joints 
  are 
  prominent, 
  in 
  this 
  case 
  the 
  east- 
  west 
  set. 
  Of 
  

   the 
  vertical 
  joints 
  the 
  northeast 
  set 
  is 
  the 
  most 
  prominent, 
  the 
  

   north 
  and 
  the 
  northwest 
  less 
  so 
  and 
  more 
  irregular. 
  The 
  Paleozoic 
  

   rocks 
  are 
  not 
  very 
  sharply 
  jointed 
  in 
  the 
  main, 
  and 
  the 
  joint 
  direc- 
  

   tions 
  are 
  very 
  irregular. 
  

  

  