﻿GEOLOGY 
  OF 
  SARATOGA 
  . 
  SPRINGS 
  AND 
  VICINITY 
  43 
  

  

  the 
  Tribes 
  Hill 
  limestone, 
  may 
  have 
  been 
  deposited 
  here 
  and 
  later 
  

   removed 
  by 
  erosion. 
  The 
  remainder 
  of 
  the 
  Beekmantown 
  was 
  

   probably 
  never 
  deposited 
  about 
  Saratoga 
  or 
  along 
  the 
  Mohawk. 
  

  

  Description. 
  The 
  Little 
  Falls 
  dolomite 
  is 
  composed 
  chiefly 
  of 
  

   rather 
  massive 
  beds 
  of 
  gray 
  dolomite. 
  The 
  larger 
  part 
  of 
  the 
  for- 
  

   mation 
  consists 
  of 
  dark 
  gray, 
  fine 
  grained 
  beds. 
  Many 
  of 
  these 
  

   contain 
  some 
  calcite, 
  chiefly 
  as 
  a 
  cement 
  binding 
  the 
  dolomite 
  crys- 
  

   tals 
  together. 
  On 
  weathered 
  surfaces 
  the 
  dolomite 
  is 
  the 
  more 
  

   resistent 
  of 
  the 
  two, 
  the 
  calcite 
  is 
  dissolved, 
  leaving 
  somewhat 
  pro- 
  

   jecting 
  dolomite 
  crystals 
  and 
  giving 
  a 
  porous, 
  sandy 
  appearance 
  to 
  

   the 
  weathered 
  surface. 
  Beds 
  of 
  this 
  type 
  are 
  best 
  exposed 
  along 
  

   North 
  Broadway 
  as 
  the 
  road 
  climbs 
  the 
  hill 
  south 
  of 
  St 
  Clements. 
  

  

  In 
  addition 
  there 
  is 
  a 
  considerable 
  thickness 
  of 
  more 
  coarsely 
  

   crystalline, 
  lighter 
  colored 
  dolomite 
  in 
  the 
  formation. 
  About 
  Sara- 
  

   toga 
  such 
  beds 
  form 
  the 
  summit 
  of 
  the 
  formation 
  and 
  are 
  exposed 
  

   in 
  many 
  places, 
  perhaps 
  best 
  in 
  the 
  Maple 
  Avenue 
  quarry. 
  They 
  

   are, 
  in 
  general, 
  quite 
  pure 
  dolomite, 
  lacking 
  the 
  calcite 
  cement 
  which 
  

   occurs 
  so 
  generally 
  in 
  the 
  darker 
  beds 
  (plate 
  8). 
  

  

  It 
  is 
  impossible 
  to 
  get 
  any 
  very 
  correct 
  idea 
  of 
  the 
  thickness 
  of 
  

   the 
  Little 
  Falls 
  dolomite, 
  from 
  the 
  exposures 
  of 
  the 
  quadrangle. 
  

   There 
  is 
  not 
  sufficient 
  variation 
  in 
  the 
  character 
  of 
  the 
  rock 
  to 
  en- 
  

   able 
  one 
  to 
  assign 
  the 
  beds 
  of 
  the 
  scattered 
  exposures 
  to 
  their 
  proper 
  

   horizon 
  in 
  the 
  formation; 
  and 
  faults 
  so 
  abound 
  that 
  nothing 
  like 
  a 
  

   continuous 
  section 
  of 
  the 
  entire 
  formation 
  exists 
  in 
  the 
  region. 
  At 
  

   Saratoga 
  Springs 
  the 
  exposures 
  are 
  in 
  a 
  triangular 
  fault 
  block, 
  and 
  

   the 
  exposed 
  thickness 
  is 
  119 
  feet. 
  1 
  This 
  is 
  the 
  upper 
  portion 
  of 
  the 
  

   formation 
  and 
  gives 
  no 
  clue 
  to 
  the 
  amount 
  beneath 
  which 
  is 
  lacking. 
  

   Two 
  deep 
  wells 
  have 
  been 
  drilled 
  at 
  Saratoga 
  with 
  the 
  diamond 
  

   drill, 
  with 
  careful 
  preservation 
  of 
  the 
  drill 
  cores, 
  one 
  at 
  the 
  Con- 
  

   gress 
  and 
  the 
  other 
  at 
  the 
  Hathorn 
  spring. 
  We 
  have 
  had 
  the 
  oppor- 
  

   tunity 
  to 
  study 
  the 
  former, 
  though 
  we 
  have 
  unfortunately 
  not 
  been 
  

   able 
  to 
  see 
  the 
  latter. 
  Each 
  well 
  went 
  down 
  near 
  the 
  Saratoga 
  fault, 
  

   and 
  each 
  must 
  rest 
  under 
  the 
  suspicion 
  of 
  having 
  crossed 
  a 
  small 
  

   branch 
  of 
  the 
  fault 
  in 
  such 
  way 
  as 
  to 
  duplicate 
  part 
  of 
  the 
  well 
  

   section 
  and 
  increase 
  the 
  apparent 
  thickness. 
  In 
  the 
  Congress 
  well 
  

   18 
  feet, 
  2 
  inches 
  of 
  drift 
  was 
  passed 
  through, 
  then 
  18 
  feet, 
  7 
  inches 
  

   of 
  Amsterdam 
  limestone, 
  after 
  which 
  the 
  entire 
  core 
  of 
  the 
  well, 
  

   some 
  281 
  feet, 
  consisted 
  of 
  Little 
  Falls 
  dolomite. 
  The 
  upper 
  40 
  

   feet 
  of 
  this 
  was 
  of 
  the 
  characteristic 
  coarsely 
  crystalline, 
  light 
  

   colored 
  dolomite 
  which 
  forms 
  the 
  upper 
  part 
  of 
  the 
  formation 
  about 
  

  

  1 
  N. 
  Y. 
  State 
  Mus. 
  Bui. 
  140, 
  p. 
  108-9. 
  

  

  