﻿GEOLOGIC 
  FOEMATIONS 
  OF 
  NEW 
  TOEK 
  149 
  

  

  It 
  attains 
  an 
  entire 
  thickness 
  of 
  more 
  than 
  300 
  feet, 
  and, 
  suc- 
  

   ceeding 
  the 
  lower 
  rocks 
  as 
  already 
  described, 
  its 
  edges 
  surround 
  

   the 
  great 
  Adirondack 
  region 
  in 
  an 
  almost 
  unbroken 
  circuit. 
  Seen 
  

   at 
  Glens 
  Falls 
  on 
  the 
  Hudson, 
  along 
  the 
  Mohawk 
  at 
  Fort 
  Plain 
  

   and 
  elsewhere, 
  on 
  the 
  west 
  shore 
  of 
  Lake 
  Champlain, 
  and 
  at 
  

   many 
  points 
  on 
  the 
  shores 
  of 
  the 
  St 
  Lawrence, 
  it 
  also 
  outcrops 
  

   along 
  the 
  valley 
  of 
  the 
  Black 
  river 
  and 
  is 
  crossed 
  by 
  West 
  Canada 
  

   creek 
  at 
  Trenton 
  Falls, 
  from 
  which 
  place 
  it 
  takes 
  its 
  name. 
  

  

  In 
  many 
  places 
  it 
  furnishes 
  building 
  stone 
  of 
  excellent 
  quality. 
  

  

  Hudson 
  River 
  Group 
  

  

  This 
  formation, 
  which 
  is 
  next 
  in 
  upward 
  succession, 
  is 
  an 
  enor- 
  

   mous 
  deposit 
  of 
  sandstone, 
  slate 
  and 
  shale. 
  The 
  lower 
  part 
  of 
  

   the 
  Hudson 
  river 
  group 
  is 
  a 
  fissile 
  black 
  slate 
  about 
  75 
  feet 
  thick, 
  

   known 
  as 
  the 
  Utica 
  slate. 
  

  

  The 
  higher 
  strata, 
  to 
  which 
  the 
  name 
  of 
  the 
  Hudson 
  river 
  

   group 
  is 
  more 
  usually 
  restricted, 
  are 
  gray 
  slaty 
  masses, 
  with 
  

   coarse 
  sandstones, 
  especially 
  toward 
  the 
  top, 
  and 
  in 
  some 
  places 
  

   near 
  the 
  summit 
  of 
  the 
  group, 
  a 
  coarse 
  sparry 
  limestone. 
  

  

  In 
  the 
  eastern 
  part 
  of 
  the 
  state 
  these 
  rocks 
  are 
  3,500 
  feet 
  thick, 
  

   as 
  shown 
  by 
  a 
  boring 
  near 
  Altamont 
  in 
  Albany 
  county. 
  They 
  

   are 
  well 
  seen 
  in 
  the 
  north 
  of 
  Oswego 
  county, 
  near 
  Pulaski, 
  the 
  

   south 
  of 
  Lewis 
  county 
  and 
  the 
  middle 
  of 
  Oneida 
  county; 
  also 
  

   through 
  the 
  Mohawk 
  valley, 
  and 
  from 
  Glens 
  Falls 
  southward 
  

   along 
  the 
  Hudson 
  river, 
  from 
  which 
  these 
  strata 
  take 
  their 
  name. 
  

   West 
  of 
  Schenectady 
  they 
  are 
  generally 
  level 
  and 
  undisturbed; 
  

   but 
  near 
  the 
  Hudson 
  river 
  these 
  strata 
  are 
  upheaved, 
  broken, 
  

   folded 
  and 
  faulted 
  in 
  every 
  conceivable 
  manner, 
  as 
  may 
  well 
  be 
  

   seen 
  in 
  many 
  places 
  near 
  Cohoes 
  and 
  Albany 
  and 
  along 
  the 
  Hud- 
  

   son 
  river 
  railroad. 
  In 
  much 
  of 
  this 
  disturbed 
  region 
  the 
  rock 
  

   has 
  been 
  changed 
  in 
  texture 
  by 
  the 
  forces 
  to 
  which 
  it 
  has 
  been 
  

   subjected 
  and 
  fossils 
  are 
  very 
  rare. 
  

  

  That 
  part 
  of 
  New 
  York 
  lying 
  east 
  of 
  the 
  Hudson, 
  and 
  along 
  

   the 
  western 
  border 
  of 
  New 
  England 
  is 
  formed 
  of 
  an 
  enormous 
  

   mass 
  of 
  upheaved 
  and 
  contorted 
  strata 
  of 
  slate, 
  schist 
  sandstone 
  

   and 
  limestone, 
  which 
  were 
  at 
  one 
  time 
  supposed 
  to 
  be 
  older 
  than 
  

  

  