﻿504 
  Forty-seventh 
  Report 
  on 
  tee 
  State 
  Museum. 
  

  

  gunk 
  grit 
  attains 
  great 
  thickness, 
  it 
  lies 
  on 
  an 
  eroded 
  surface 
  of 
  

   the 
  Hudson 
  river 
  shales 
  throughout. 
  These 
  relations 
  are 
  due 
  to 
  

   an 
  uplift 
  with 
  erosion 
  at 
  the 
  end 
  of 
  lower 
  Silurian 
  times 
  and 
  

   probably 
  also 
  to 
  oscillations 
  for 
  a 
  considerable 
  part 
  of 
  the 
  early 
  

   upper 
  Silurian. 
  Mather 
  and 
  Davis 
  have 
  discussed 
  some 
  of 
  the 
  

   relations 
  in 
  the 
  Hudson 
  valley, 
  and 
  Dr. 
  James 
  Hall 
  has 
  reviewed 
  

   the 
  principal 
  features 
  in 
  several 
  papers. 
  

  

  The 
  sequence 
  of 
  events 
  in 
  Ulster 
  county 
  was 
  a 
  general 
  uplift 
  

   of 
  the 
  deposits 
  at 
  the 
  close 
  of 
  the 
  Hudson 
  river 
  deposition, 
  and 
  

   erosion 
  of 
  its 
  entire 
  surface. 
  The 
  uplift 
  was 
  attended 
  by 
  con- 
  

   siderable 
  folding, 
  the 
  greatest 
  in 
  amount 
  to 
  the 
  northwestward 
  

   and 
  the 
  flexures 
  were 
  base 
  leveled 
  in 
  some 
  measure. 
  The 
  Oneida, 
  

   Medina 
  and 
  Clinton 
  appear 
  to 
  have 
  been 
  deposited 
  during 
  subsi- 
  

   dence 
  which 
  increased 
  southward 
  so 
  that 
  the 
  deposits 
  overlapped, 
  

   the 
  latest 
  extending 
  nearly 
  to 
  Kingston. 
  Possibly 
  there 
  was 
  

   some 
  deposition 
  farther 
  south 
  which 
  was 
  removed 
  by 
  uplifts 
  and 
  

   erosion 
  of 
  which 
  there 
  is 
  now 
  no 
  evidence. 
  The 
  absence 
  of 
  the 
  

   Niagara 
  southward, 
  and 
  its 
  thinning 
  north 
  of 
  East 
  Kingston, 
  

   may 
  be 
  due 
  either 
  to 
  cessation 
  of 
  deposition, 
  or 
  to 
  uplifts 
  of 
  the 
  

   surface 
  above 
  the 
  waters 
  of 
  Niagara 
  times. 
  With 
  the 
  deposition 
  

   of 
  the 
  Salina 
  beds 
  there 
  was 
  general 
  subsidence 
  which 
  was 
  long 
  

   continued. 
  

  

  Hudson 
  river 
  formation— 
  - 
  This 
  formation 
  consists 
  of 
  shales 
  

   and 
  sandstones. 
  The 
  shales 
  vary 
  from 
  gray-brown 
  to 
  black 
  in 
  

   color, 
  are 
  fissile, 
  moderately 
  hard 
  for 
  the 
  most 
  part, 
  and 
  give 
  rise* 
  

   to 
  rounded 
  hills 
  which, 
  in 
  the 
  vicinity 
  of 
  Shawangunk 
  mountain, 
  

   are 
  of 
  considerable 
  height. 
  They 
  contain 
  intercalated 
  beds 
  of 
  

   sandstone 
  of 
  two 
  kinds, 
  one 
  a 
  very 
  fine-grained, 
  massively 
  bedded, 
  

   dark-gray 
  or 
  blue-black 
  hard 
  sandstone, 
  of 
  which 
  there 
  are 
  beds 
  

   occurring 
  widely 
  scattered 
  throughout 
  the 
  formation 
  ; 
  and 
  the 
  

   other, 
  a 
  succession 
  of 
  coarse-grained, 
  dark 
  gray, 
  thin-bedded 
  flaggy 
  

   sandstones 
  with 
  disseminated 
  pebbles 
  of 
  quartz, 
  slate, 
  and 
  lime- 
  

   stone 
  occurring 
  in 
  a 
  series 
  of 
  ridges 
  extending 
  northward 
  through 
  

   the 
  southeastern 
  corner 
  of 
  the 
  county. 
  The 
  stratigraphy 
  of 
  the 
  

   formation 
  has 
  not 
  been 
  worked 
  out, 
  and 
  owing 
  to 
  the 
  complicated 
  

   structure 
  and 
  lack 
  of 
  knowledge 
  of 
  the 
  stratigraphy, 
  the 
  thickness 
  

   of 
  the 
  formation 
  in 
  Ulster 
  county 
  has 
  not 
  been 
  determined. 
  

  

  