﻿GEOLOGY 
  OF 
  SARATOGA 
  SPRINGS 
  AND 
  VICINITY 
  107 
  

  

  tions 
  that 
  the 
  uppermost 
  thrust 
  plane, 
  that 
  of 
  the 
  Georgian, 
  is 
  the 
  

   youngest, 
  while 
  Mr 
  Willis 
  considers 
  the 
  lowest, 
  the 
  great 
  major 
  

   thrust 
  C 
  of 
  his 
  diagram 
  as 
  the 
  youngest. 
  

  

  The 
  appearance 
  of 
  a 
  narrow 
  belt 
  of 
  Schaghticoke 
  shale 
  between 
  

   Schuylerville 
  and 
  Thomson 
  is 
  evidence 
  of 
  a 
  fault 
  in 
  that 
  section, 
  

   for 
  since 
  the 
  Schaghticoke 
  is 
  separated 
  by 
  the 
  considerable 
  thick- 
  

   ness 
  of 
  Deep 
  Kill 
  shales 
  from 
  the 
  Normanskill 
  shale 
  and 
  these 
  are 
  

   absent 
  at 
  Schuylerville, 
  1 
  a 
  single 
  anticline 
  would 
  not 
  explain 
  the 
  

   occurrence. 
  It 
  is 
  either 
  a 
  mass, 
  entirely 
  separated 
  from 
  its 
  roots 
  

   in 
  the 
  contorted 
  and 
  crumpled 
  shale 
  mass, 
  or 
  a 
  small 
  fault 
  block 
  

   thrust 
  through 
  the 
  other 
  shales. 
  Close 
  by 
  is 
  the 
  " 
  Northumber- 
  

   land 
  volcanic 
  plug," 
  which 
  also 
  is 
  cut 
  by 
  slickensided 
  planes 
  strik- 
  

   ing 
  in 
  the 
  general 
  direction 
  of 
  the 
  faults 
  of 
  the 
  area; 
  and 
  which, 
  

   according 
  to 
  Professor 
  Cushing's 
  investigations, 
  may 
  be 
  a 
  similar 
  

   small 
  block, 
  torn 
  off 
  its 
  main 
  mass 
  and 
  carried 
  forward 
  with 
  the 
  

   shale 
  masses 
  of 
  the 
  " 
  Decke." 
  2 
  

  

  The 
  structure 
  of 
  the 
  Greenwich 
  plateau. 
  The 
  Greenwich 
  

   plateau 
  enters 
  the 
  Schuylerville 
  quadrangle 
  from 
  the 
  east 
  with 
  a 
  

   belt 
  only 
  I 
  to 
  2 
  miles 
  wide. 
  We 
  have 
  to 
  distinguish 
  two 
  structures 
  

   in 
  the 
  part 
  of 
  the 
  plateau 
  with 
  which 
  we 
  are 
  concerned, 
  namely, 
  

   the 
  Willard 
  Mountain 
  syncline 
  and 
  the 
  Georgian 
  overthrust 
  mass. 
  

  

  1 
  Willard 
  Mountain 
  syncline. 
  We 
  have 
  mentioned 
  above 
  that 
  

   the 
  imposing 
  and 
  historic 
  Willard 
  mountain, 
  which 
  rises 
  boldly 
  

   more 
  than 
  1200 
  feet 
  above 
  the 
  bed 
  of 
  the 
  Hudson 
  river, 
  presents 
  

   the 
  structure 
  of 
  a 
  syncline, 
  much 
  larger 
  and 
  more 
  open 
  than 
  the 
  

   synclines 
  observed 
  in 
  the 
  shales 
  of 
  the 
  Saratoga 
  plain. 
  This 
  open 
  

   structure 
  is 
  obviously 
  due 
  to 
  the 
  presence 
  of 
  a 
  great 
  amount 
  of 
  

   grit 
  and 
  silicious, 
  cherty 
  shale 
  in 
  the 
  strata 
  folded 
  there. 
  At 
  the 
  

   northeast 
  end 
  the 
  strike 
  of 
  the 
  beds 
  swings 
  around 
  from 
  northeast 
  

   to 
  northwest, 
  suggesting 
  that 
  the 
  syncline 
  terminates 
  here 
  ab- 
  

   ruptly 
  with 
  a 
  well-rounded 
  curve. 
  At 
  the 
  eastern 
  foot 
  of 
  the 
  

   mountain 
  a 
  coarse 
  conglomerate 
  forms 
  the 
  crest 
  of 
  a 
  small 
  anticline. 
  

  

  2 
  Georgian 
  overthrust 
  blanket. 
  If 
  one 
  wanders 
  from 
  the 
  

   Hudson 
  river, 
  for 
  instance 
  at 
  Thomson 
  or 
  Clark 
  Mills 
  eastward, 
  

  

  1 
  We 
  omit 
  here 
  the 
  distant 
  possibility 
  that 
  the 
  Beekmantown 
  beds 
  could 
  be 
  

   absent 
  in 
  the 
  series 
  at 
  Schuylerville, 
  although 
  it 
  has 
  been 
  claimed 
  that 
  they 
  

   are 
  intermittent. 
  

  

  2 
  Since 
  " 
  blanket 
  " 
  corresponds 
  to 
  the 
  German 
  " 
  Decke 
  " 
  and 
  means 
  a 
  cover, 
  

   relatively 
  thin, 
  such 
  as 
  these 
  thrust 
  masses 
  are, 
  they 
  might 
  be 
  called 
  " 
  thrust 
  

   blankets." 
  The 
  word 
  " 
  sheet 
  " 
  would 
  be 
  liable 
  to 
  confusion. 
  The 
  French 
  

   " 
  carriage 
  " 
  is 
  also 
  transferable, 
  although 
  the 
  meaning 
  of 
  the 
  English 
  word 
  

   carriage 
  for 
  "that 
  which 
  is 
  carried" 
  has 
  become 
  archaic 
  (Webster). 
  

  

  