﻿Report 
  of 
  the 
  State 
  Geologist, 
  497 
  

  

  slaty 
  cleavage 
  This 
  is 
  notably 
  the 
  case 
  at 
  the 
  falls 
  caused 
  by 
  

   it 
  a 
  mile 
  northeast 
  of 
  Pattankunk. 
  

  

  From 
  Wawarsing 
  township 
  southward 
  the 
  rock 
  is 
  not 
  exposed, 
  

   so 
  far 
  as 
  I 
  know, 
  but 
  it 
  underlies 
  the 
  Sandburg 
  Creek 
  valley. 
  

  

  The 
  thickness 
  in 
  the 
  northern 
  part 
  of 
  the 
  county 
  is 
  about 
  200 
  

   feet 
  ; 
  about 
  Kingston 
  it 
  is 
  fully 
  300 
  feet, 
  but 
  southward 
  it 
  prob- 
  

   ably 
  thins 
  somewhat 
  although 
  beyond 
  Rosendale 
  I 
  could 
  find 
  no 
  

   complete 
  sections 
  from 
  which 
  an 
  estimate 
  of 
  thickness 
  could 
  be 
  

   made. 
  

  

  The 
  Orislcany 
  sandstone. 
  — 
  This 
  thin 
  but 
  characteristic 
  formation 
  

   lies 
  immediately 
  beneath 
  the 
  Esopus 
  shales, 
  either 
  at 
  the 
  base 
  of 
  

   the 
  first 
  Esopus 
  shale 
  ridge 
  or 
  constituting 
  a 
  narrow 
  ridge 
  just 
  

   east 
  or 
  south. 
  It 
  appears 
  to 
  be 
  continuous 
  throughout 
  Ulster 
  

   county 
  but 
  in 
  some 
  regions 
  is 
  hidden 
  by 
  drift 
  or 
  debris. 
  It 
  pre- 
  

   sents 
  a 
  variety 
  of 
  components 
  in 
  this 
  region, 
  some 
  of 
  which 
  were 
  

   not 
  observed 
  elsewhere. 
  In 
  greater 
  part 
  it 
  is 
  a 
  very 
  silicious 
  

   limestone, 
  but 
  about 
  Rondout 
  and 
  Wilbur 
  it 
  contains 
  a 
  bed 
  of 
  

   small 
  pebble 
  conglomerate 
  to 
  which 
  attention 
  has 
  been 
  called 
  by 
  

   Davis.* 
  The 
  thickness 
  of 
  the 
  formation 
  is 
  very 
  variable. 
  West 
  

   of 
  Saugerties, 
  seven 
  feet 
  of 
  quartzitic 
  beds 
  are 
  seen 
  ; 
  along 
  

   Esopus 
  creek 
  there 
  are 
  twelve 
  feet 
  of 
  calcareous 
  beds, 
  and 
  at 
  

   Rondout, 
  thirty 
  feet, 
  including 
  the 
  conglomeratic 
  member. 
  In 
  

   the 
  Whiteport 
  region 
  and 
  southward 
  the 
  formation 
  consists 
  of 
  a 
  

   silicious 
  limestone 
  'bed 
  which 
  has 
  a 
  thickness 
  of 
  from 
  eight 
  to 
  

   nine 
  feet. 
  ISTear 
  Wawarsing 
  the 
  thickness 
  is 
  ten 
  to 
  fifteen 
  feet. 
  

   The 
  formation 
  is 
  very 
  f 
  ossilif 
  erous 
  throughout 
  ; 
  the 
  casts 
  and 
  

   impressions 
  of 
  the 
  shells 
  appearing 
  prominently 
  in 
  the 
  weathered 
  

   surface 
  of 
  the 
  beds. 
  The 
  most 
  notable 
  occurrence 
  of 
  fossils 
  is 
  

   along 
  the 
  east 
  bank 
  of 
  Esopus 
  creek 
  below 
  Glenerie, 
  where 
  they 
  

   abound. 
  They 
  are 
  also 
  abundant 
  at 
  some 
  points 
  about 
  Rondout 
  

   and 
  along 
  the 
  Wallkill 
  Valley 
  railroad, 
  north 
  of 
  Whiteport. 
  

  

  Upper 
  Shaly 
  limestone. 
  — 
  This 
  is 
  the 
  upper 
  member 
  of 
  the 
  lower 
  

   Helderberg 
  limestone 
  formation. 
  

  

  The 
  upper 
  Shaly 
  beds 
  are 
  very 
  impure 
  limestones 
  contain- 
  

   ing 
  a 
  considerable 
  proportion 
  of 
  clay 
  and 
  sand. 
  They 
  are 
  

   somewhat 
  massively 
  bedded, 
  but 
  their 
  most 
  prominent 
  physical 
  

   feature 
  is 
  their 
  slaty 
  cleavage. 
  Owing 
  to 
  their 
  hardness 
  

  

  * 
  Nonconformity 
  at 
  Rondout. 
  Am, 
  Jour. 
  Science, 
  III, 
  vol. 
  26, 
  page 
  393. 
  

  

  63 
  

  

  