﻿GEOLOGICAL 
  SURVEY 
  OF 
  THE 
  STATE 
  OF 
  NEW 
  YORK. 
  

  

  (GEOLOGICAL 
  MAP.) 
  

  

  Report 
  on 
  the 
  Relations 
  of 
  the 
  Helderberg 
  Limestones 
  and 
  

   Associated 
  Formations 
  in 
  Eastern 
  New 
  York. 
  

  

  By 
  N. 
  H. 
  D 
  A 
  RTON. 
  

  

  1892. 
  

  

  Contents. 
  — 
  Introductory 
  — 
  Physiography 
  — 
  Stratigraphy 
  ; 
  General 
  relations 
  ; 
  

   The 
  Formations, 
  Onondaga 
  limestone, 
  Schoharie 
  grit, 
  Esopus 
  slate, 
  Oriskany 
  

   sandstone, 
  Helderberg 
  limestones, 
  Salina 
  water-lime, 
  Niagara 
  limestone, 
  

   Clinton 
  formation, 
  'Shawangunk 
  grit, 
  Hudson 
  formation. 
  The 
  overlaps 
  and 
  

   their 
  history 
  ; 
  Structure. 
  

  

  IISTRODUCTOBY. 
  

   James 
  Hall, 
  State 
  Geologist: 
  

  

  Sir. 
  — 
  In 
  the 
  autumn 
  of 
  1S92 
  I 
  was 
  assigned 
  by 
  Major 
  Powell, 
  

   Director 
  of 
  the 
  United 
  States 
  Geological 
  Survey, 
  to 
  field 
  work 
  in 
  

   the 
  State 
  of 
  New 
  York 
  under 
  the 
  direction 
  of 
  the 
  State 
  Geologist. 
  

   This 
  work 
  was 
  especially 
  undertaken 
  for 
  the 
  purpose 
  of 
  tracing 
  

   accurately 
  the 
  limits 
  of 
  the 
  several 
  formations, 
  with 
  a 
  view 
  of 
  

   affording 
  data 
  for 
  the 
  new 
  geological 
  map 
  of 
  the 
  State 
  now 
  in 
  

   course 
  of 
  publication. 
  

  

  The 
  structure 
  of 
  the 
  country 
  to 
  which 
  I 
  was 
  assigned 
  was 
  

   already 
  known 
  from 
  the 
  geological 
  survey 
  of 
  1836 
  to 
  1842, 
  but 
  

   that 
  work 
  having 
  been 
  laid 
  down 
  upon 
  unreliable 
  maps 
  it 
  became 
  

   necessary 
  to 
  go 
  over 
  the 
  ground 
  with 
  more 
  accurate 
  maps 
  in 
  hand 
  

   for 
  the 
  purpose 
  of 
  fixing 
  the 
  boundary 
  lines 
  of 
  each 
  formation. 
  

  

  During 
  the 
  months 
  of 
  September 
  and 
  October 
  I 
  was 
  occupied 
  

   with 
  this 
  work, 
  my 
  observations 
  extending 
  from 
  Ellenville, 
  in 
  

   Ulster 
  county, 
  to 
  the 
  Niagara 
  river, 
  but 
  detailed 
  examinations 
  

   were 
  confined 
  to 
  the 
  country 
  east 
  and 
  south 
  of 
  Howe's 
  Cave 
  and 
  

   Schoharie 
  creek. 
  To 
  this 
  region 
  I 
  devoted 
  about 
  one 
  month 
  of 
  

   50 
  

  

  