﻿62 
  

  

  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  of 
  the 
  Little 
  Falls 
  dolomite, 
  and 
  is 
  today 
  best 
  shown 
  back 
  of 
  the 
  

   High 
  Rock 
  spring 
  (plate 
  8). 
  Small 
  patches 
  of 
  basal 
  Amsterdam 
  

   lying 
  in 
  contact 
  with 
  the 
  Little 
  Falls 
  somewhat 
  farther 
  north 
  show 
  

   that 
  this 
  is 
  the 
  very 
  summit 
  of 
  the 
  formation. 
  At 
  the 
  Star 
  spring 
  

   a 
  wedge 
  of 
  Amsterdam 
  limestone 
  appears 
  lying 
  closely 
  against 
  the 
  

   fault 
  face 
  and 
  with 
  a 
  tipped 
  upper 
  surface, 
  rising 
  toward 
  the 
  north, 
  

   falling 
  toward 
  the 
  south. 
  Back 
  of 
  the 
  Red 
  spring 
  it 
  has 
  risen 
  to 
  

   the 
  full 
  height 
  of 
  the 
  fault 
  scarp; 
  at 
  the 
  High 
  Rock 
  spring 
  it 
  is 
  

   some 
  15 
  feet 
  below 
  the 
  surface 
  of 
  the 
  ground. 
  Figures 
  6 
  and 
  7 
  

   clearly 
  show 
  the 
  disposition 
  of 
  this 
  wedge 
  of 
  Amsterdam. 
  

  

  Fig. 
  7 
  Illustration 
  of 
  the 
  manner 
  in 
  which 
  the 
  tipped 
  block 
  of 
  Amsterdam 
  

   limestone 
  lies 
  against 
  the 
  fault 
  face, 
  as 
  -seen 
  in 
  looking 
  at 
  the 
  fault 
  from 
  

   the 
  downthrow 
  side; 
  tilt 
  of 
  block 
  much 
  exaggerated; 
  1 
  = 
  Red 
  spring, 
  2^ 
  

   Star 
  spring, 
  3 
  = 
  High 
  Rock 
  spring. 
  

  

  At 
  the 
  Star 
  spring 
  a 
  drilled 
  well 
  gave 
  38 
  feet 
  of 
  drift 
  and 
  62 
  

   feet 
  of 
  shale 
  before 
  reaching 
  the 
  summit 
  of 
  the 
  Amsterdam 
  lime- 
  

   stone. 
  This 
  well 
  is 
  only 
  a 
  very 
  few 
  yards 
  east 
  of 
  the 
  Amsterdam 
  

   wedge 
  outcrop 
  and 
  the 
  fault 
  line, 
  showing 
  clearly 
  that 
  the 
  wedge 
  

   is 
  but 
  a 
  very 
  narrow 
  block 
  caught 
  in 
  along 
  the 
  fault. 
  Ignoring 
  

   it 
  and 
  estimating 
  the 
  throw 
  of 
  the 
  Saratoga 
  fault 
  from 
  the 
  ex- 
  

   posures 
  and 
  the 
  well 
  record 
  at 
  the 
  Star 
  spring, 
  a 
  result 
  of 
  about 
  160 
  

   feet 
  is 
  obtained, 
  100 
  feet 
  of 
  drift 
  and 
  shale, 
  40 
  feet 
  of 
  Amsterdam 
  

   limestone 
  and 
  the 
  20 
  feet 
  of 
  Little 
  Falls 
  shown 
  in 
  the 
  fault 
  scarp. 
  

  

  The 
  Amsterdam 
  wedge 
  seems 
  to 
  continue 
  along 
  the 
  fault 
  all 
  

   the 
  way 
  through 
  Saratoga 
  between 
  the 
  two 
  swerves 
  in 
  its 
  course. 
  

   This 
  is 
  indicated 
  by 
  the 
  fact 
  that 
  it 
  is 
  the 
  surface 
  rock 
  just 
  east 
  of 
  

   the 
  fault 
  at 
  the 
  Hathorn 
  spring, 
  and 
  also 
  is 
  the 
  surface 
  rock 
  at 
  the 
  

   Congress 
  spring, 
  as 
  shown 
  by 
  the 
  drill 
  core. 
  It 
  really 
  amounts 
  to 
  a 
  

   parallel 
  fault 
  lying 
  very 
  close 
  to 
  the 
  main 
  fault. 
  South 
  of 
  the 
  Con- 
  

   gress 
  spring 
  its 
  course 
  is 
  lost 
  under 
  heavy 
  drift. 
  

  

  