﻿Report 
  of 
  the 
  State 
  Geologist. 
  

  

  421 
  

  

  the 
  Hudson 
  river 
  and 
  older 
  formations, 
  but 
  the 
  eastern 
  edge 
  of 
  

   the 
  Helderberg 
  formations 
  extends 
  eastward 
  on 
  to 
  it 
  for 
  some 
  

   distance 
  from 
  Albany 
  county 
  southward, 
  in 
  a 
  belt 
  from 
  one 
  to 
  

   four 
  miles 
  in 
  width, 
  in 
  which 
  are 
  presented 
  the 
  typical 
  features 
  

   of 
  Appalachian 
  structure 
  but 
  on 
  a 
  somewhat 
  reduced 
  scale. 
  

   Davis* 
  has 
  described 
  the 
  structure 
  about 
  Catskill 
  and 
  Rondout, 
  

   and 
  Mather 
  refers 
  in 
  his 
  reports, 
  to 
  various 
  features 
  of 
  the 
  region. 
  

   Mather, 
  however, 
  misinterpreted 
  the 
  structure 
  ia 
  most 
  cases, 
  

   notably 
  in 
  mistaking 
  Esopus 
  shales 
  for 
  Hudson 
  river 
  shales 
  and 
  

   the 
  sections 
  on 
  plates 
  7 
  and 
  8 
  in 
  his 
  final 
  report 
  are 
  in 
  greater 
  

   part 
  erroneous. 
  

  

  The 
  Monoclinal 
  region. 
  — 
  The 
  structure 
  in 
  the 
  monoclinal 
  region 
  

   from 
  Schoharie 
  to 
  the 
  Helderberg 
  mountains 
  is 
  very 
  simple, 
  and 
  

   is 
  shown 
  in 
  figures 
  4 
  and 
  5. 
  

  

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  Fig. 
  4. 
  — 
  Diagram 
  of 
  West 
  mountain, 
  Schoharie. 
  

  

  "West 
  mountain 
  beautifully 
  illustrates 
  the 
  sequence 
  and 
  topo- 
  

   graphic 
  products 
  of 
  the 
  formations 
  in 
  its- 
  great 
  escarpment 
  and 
  

   terraces 
  and 
  has 
  long 
  been 
  known 
  as 
  a 
  typical 
  exposure 
  of 
  the 
  

   Helderberg 
  rocks. 
  

  

  The 
  rate 
  of 
  dip 
  in 
  this 
  region 
  was 
  estimated 
  from 
  aneroid 
  

   observations, 
  and 
  the 
  sections 
  shown 
  in 
  figures 
  11 
  and 
  12 
  were 
  

   constructed 
  by 
  this 
  means. 
  About 
  Schoharie 
  on 
  section 
  1, 
  figures 
  

   9 
  and 
  10, 
  the 
  rate 
  is 
  100 
  feet 
  per 
  mile, 
  on 
  section 
  2, 
  figure 
  11, 
  115 
  

   feet, 
  and 
  on 
  section 
  3, 
  150 
  feet. 
  These, 
  it 
  should 
  be 
  understood, 
  

   are 
  not 
  precise 
  determinations, 
  for 
  although 
  the 
  aneroid 
  readings 
  

  

  *The 
  little 
  mountains 
  east 
  of 
  the 
  Catskills; 
  the 
  folded 
  Helderberg 
  limestones 
  east 
  of 
  the 
  Cats- 
  

   kills, 
  and 
  the 
  nonconformity 
  at 
  Rondout 
  ut 
  . 
  dt. 
  

  

  