﻿REPORT 
  OF 
  THE 
  DIRECTOR 
  10,12 
  10, 
  

  

  West 
  Branch 
  and 
  Northville 
  ; 
  and 
  in 
  the 
  valley 
  of 
  the 
  West 
  

   Branch 
  in 
  the 
  vicinity 
  of 
  Whitehouse. 
  

  

  During 
  the 
  year 
  we 
  have 
  issued 
  a 
  bulletin 
  on 
  the 
  Mineral 
  

   Springs 
  of 
  Saratoga, 
  prepared 
  by 
  James 
  F. 
  Kemp, 
  in 
  con- 
  

   nection 
  with 
  the 
  series 
  of 
  investigations 
  of 
  the 
  Saratoga 
  district 
  

   which 
  have 
  been 
  in 
  progress 
  for 
  several 
  years. 
  The 
  region 
  here 
  

   concerned 
  is 
  covered 
  by 
  the 
  Saratoga 
  and 
  Schuylerville 
  quad- 
  

   rangles 
  and 
  the 
  rock 
  geology, 
  especially 
  intricate 
  in 
  the 
  latter 
  

   quadrangle, 
  has 
  now 
  been 
  finally 
  mapped 
  by 
  Doctors 
  Gushing 
  

   and 
  Ruedemann. 
  Features 
  of 
  special 
  importance 
  in 
  the 
  Schuy- 
  

   lerville 
  region 
  are 
  the 
  great 
  overthrusts 
  and 
  overturned 
  folds 
  in 
  

   the 
  Bald 
  mountain 
  district 
  and 
  the 
  problem 
  presented 
  by 
  the 
  

   Schuylerville 
  volcanic 
  plug 
  penetrating 
  the 
  Paleozoic 
  slates. 
  The 
  

   latter 
  has 
  been 
  much 
  debated. 
  The 
  shales 
  about 
  the 
  volcanic 
  

   mass 
  have 
  been 
  distinctly 
  overthrust 
  and 
  it 
  seems 
  very 
  evident 
  

   that 
  the 
  eruptive 
  has 
  been 
  involved 
  in 
  this 
  movement. 
  There 
  

   are 
  reasons 
  for 
  regarding 
  the 
  plug 
  as 
  of 
  Postpaleozoic 
  age 
  and 
  

   as 
  thrust 
  by 
  lateral 
  shove 
  many 
  miles 
  westward 
  of 
  its 
  original 
  

   position. 
  

  

  The 
  investigation 
  of 
  the 
  structure 
  of 
  the 
  shale 
  belt 
  of 
  the 
  

   Schuylerville 
  and 
  Saratoga 
  sheets 
  has 
  led 
  to 
  the 
  inference 
  that 
  

   the 
  mineral 
  waters 
  of 
  Saratoga 
  fill 
  a 
  wide 
  basin 
  below 
  the 
  shale 
  

   formed 
  by 
  the 
  Potsdam 
  sandstone 
  and 
  overlying 
  Cambric 
  and 
  

   Ordovicic 
  limestones 
  and 
  that 
  the 
  water 
  of 
  the 
  Saratoga 
  springs 
  

   is 
  derived 
  by 
  filtration 
  through 
  mountain 
  folds 
  about 
  the 
  Hud- 
  

   son 
  river 
  and 
  carried 
  westward 
  under 
  the 
  thick 
  cover 
  of 
  the 
  

   Canajoharie 
  shales 
  to 
  the 
  Saratoga-Mount 
  McGregor 
  fault 
  and 
  its 
  

   branches, 
  where 
  it 
  finds 
  the 
  thinnest 
  cover 
  of 
  shale 
  and 
  thus 
  

   escapes. 
  The 
  Canajoharie 
  shale 
  rapidly 
  thickens 
  southward 
  on 
  

   account 
  of 
  its 
  dip, 
  and 
  the 
  projecting 
  fault 
  blocks 
  of 
  Precambric 
  

   rocks 
  close 
  the 
  basin 
  to 
  the 
  northward. 
  

  

  Outside 
  of 
  this 
  immediate 
  region, 
  the 
  work 
  in 
  the 
  shale 
  belt 
  

   has 
  further 
  brought 
  out 
  the 
  fact 
  that 
  the 
  thick 
  formation 
  of 
  the 
  

   Normanskill 
  shale 
  comprises 
  two 
  divisions, 
  a 
  lower 
  one 
  corre- 
  

   sponding 
  to 
  the 
  Chazy, 
  and 
  an 
  upper, 
  corresponding 
  to 
  the. 
  Low- 
  

   ville-Black 
  river 
  interval. 
  Normanskill 
  shale 
  graptolites 
  were 
  

   found 
  in 
  shale 
  intercalated 
  in 
  the 
  grit 
  beds 
  extending 
  many 
  miles 
  

   along 
  the 
  Hudson 
  about 
  Hyde 
  Park, 
  N. 
  Y., 
  indicating 
  that 
  the 
  

   shale 
  belt 
  there 
  may 
  be 
  largely 
  of 
  Normanskill 
  age. 
  The 
  broad 
  

   belt 
  of 
  rocks 
  extending 
  from 
  Schodack 
  Landing 
  to 
  Stockport 
  

   has 
  hitherto 
  been 
  entered 
  as 
  Georgian 
  on 
  the 
  State 
  map, 
  but 
  

   the 
  larger 
  middle 
  part 
  of 
  this 
  is 
  now 
  known 
  to 
  consist 
  of 
  Deepkill 
  

  

  