﻿Report 
  of 
  tee 
  State 
  Geologist. 
  397 
  

  

  burner* 
  with 
  the 
  Helderberg 
  formation 
  according 
  to 
  my 
  own 
  

   interpretation. 
  The 
  sections 
  at 
  Catskill 
  and 
  Kondout 
  are 
  from 
  

   Davis, 
  with 
  slight 
  modifications, 
  and 
  the 
  Xew 
  Jersey 
  column 
  

   is 
  mainly 
  compiled 
  from 
  the 
  publication 
  of 
  I. 
  C. 
  White 
  4 
  - 
  and 
  

   Barrett. 
  

  

  The 
  datum 
  line 
  for 
  these 
  sections 
  is 
  the 
  base 
  of 
  the 
  Hamilton 
  

   group 
  which 
  is 
  a 
  remarkably 
  continuous 
  and 
  sharply-defined 
  

   horizon 
  throughout. 
  The 
  transition 
  from 
  limestone 
  to 
  shales 
  is 
  

   everywhere 
  abrupt, 
  and 
  I 
  believe 
  constant 
  in 
  horizon 
  from 
  Penn- 
  

   sylvania 
  through 
  Xew 
  York 
  to 
  western 
  Canada. 
  

  

  The 
  only 
  important 
  variation 
  in 
  the 
  Onondaga 
  limestone 
  is 
  

   the 
  diminution 
  of 
  its 
  thickness 
  for 
  some 
  distance 
  southward 
  from 
  

   the 
  Helderberg 
  mountains 
  and 
  its 
  great 
  expansion 
  in 
  northern 
  

   New 
  Jersey. 
  It 
  is 
  everywhere 
  a 
  blue-gray 
  pure 
  limestone, 
  pre- 
  

   dominantly 
  cherty 
  in 
  its 
  upper 
  portion. 
  In 
  western 
  Xew 
  York 
  

   and 
  in 
  Pennsylvania 
  it 
  comprises 
  several 
  more 
  or 
  less 
  distinctly 
  

   separable 
  members, 
  but 
  in 
  eastern 
  Xew 
  York 
  subdivisional 
  dis- 
  

   tinctions 
  are 
  not 
  obvious. 
  In 
  plate 
  1 
  the 
  Schoharie 
  grit 
  is 
  not 
  

   indicated. 
  This 
  is 
  a 
  thin 
  member 
  which 
  appears 
  to 
  be 
  a 
  local 
  

   phase 
  of 
  the 
  earlier 
  Onondaga 
  deposits 
  in 
  the 
  Schoharie 
  and 
  

   Helderberg 
  region, 
  although 
  strongly 
  characterized 
  by 
  its 
  dis- 
  

   tinctive 
  fauna. 
  The 
  shales 
  and 
  slates 
  which 
  have 
  been 
  known 
  

   as 
  the 
  " 
  Caudi-galli 
  grit 
  " 
  attain 
  their 
  maximum 
  development 
  

   in 
  Xew 
  York 
  about 
  Catskill 
  and 
  Kingston, 
  thinning 
  gradually 
  

   to 
  seventy 
  feet 
  at 
  Schoharie, 
  forty 
  feet 
  near 
  Jordansvilie. 
  north 
  

   of 
  Pdchfield 
  Springs, 
  three 
  Feet 
  at 
  Columbia, 
  northwest 
  of 
  Kich- 
  

   field 
  Springs, 
  and 
  it 
  is 
  entirely 
  absent 
  at 
  Litchfield, 
  eight 
  miles 
  

   farther 
  west. 
  This 
  rock 
  expands 
  greatly 
  in 
  Xew 
  Jersey. 
  

  

  The 
  Oriskany 
  sandstone 
  is 
  a 
  thru, 
  irregular 
  predominantly 
  

   arenaceous 
  deposit 
  overlying 
  the 
  Caudi-galli 
  beds 
  and 
  extending 
  

   westward 
  in 
  disconnected 
  outliers 
  to 
  a 
  considerable 
  distance 
  

   beyond 
  Cayuga 
  lake. 
  In 
  eastern 
  ZS"ew 
  York 
  it 
  is 
  often 
  very 
  cal- 
  

   careous, 
  or 
  cherty. 
  In 
  Greene 
  county 
  it 
  is 
  discontinuous 
  over 
  a 
  

  

  ♦Petroleum 
  and 
  natural 
  gas 
  in 
  Xew 
  York 
  State. 
  Am. 
  Inst. 
  Mining 
  Engineers. 
  Trans., 
  vol. 
  16, 
  

   pp. 
  9:6-953, 
  plates. 
  1889. 
  

  

  t 
  Second 
  Geol. 
  Survey 
  of 
  Perm. 
  Report 
  06. 
  Pike 
  and 
  Monroe 
  counties, 
  pp. 
  74-75. 
  1882. 
  

   "Notes 
  on 
  the 
  Lower 
  Helderberg 
  rocks 
  of 
  Port 
  Jervis. 
  X 
  Y 
  ." 
  X. 
  Y. 
  Lyceum 
  of 
  Nat. 
  Hist. 
  

   Annals, 
  vol. 
  11. 
  pp. 
  890-899, 
  1876, 
  and 
  Am. 
  Jour. 
  Sci.. 
  3d 
  series, 
  vol. 
  13,'pp. 
  385-387. 
  1877. 
  •'The 
  

   Coralline 
  or 
  Niagara 
  Limestone 
  of 
  the 
  Appalachian 
  syctem 
  as 
  represented 
  at 
  Nearpass"s 
  Cliff. 
  

   Montague, 
  New 
  Jersey." 
  Am. 
  Jour. 
  Sci.. 
  3d 
  series, 
  vol. 
  15. 
  pp 
  370-372. 
  1878. 
  

  

  