﻿452 
  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  were 
  buckled 
  downward 
  and 
  backward 
  under 
  the 
  soft 
  shales, 
  as 
  

   indicated 
  by 
  the 
  arrows 
  in 
  II 
  before 
  they 
  were 
  also 
  fractured. 
  

   The 
  lower 
  limestones 
  were 
  also 
  considerably 
  broken 
  and 
  cross- 
  

   faulted, 
  as 
  shown 
  in 
  the 
  figures. 
  The 
  aniou 
  it 
  of 
  displacement 
  of 
  

   the 
  over 
  thrust 
  is 
  about 
  100 
  feet. 
  The 
  force 
  was 
  exerted 
  from 
  

   the 
  eastward 
  and 
  almost 
  horizontally 
  in 
  direction, 
  unless 
  the 
  

   present 
  low 
  angle 
  between 
  fault 
  line 
  and 
  axial 
  planes 
  is 
  due 
  to 
  

   subsequent 
  tilting. 
  

  

  Down 
  the 
  creek 
  from 
  the 
  overthrust 
  the 
  Hudson 
  river 
  shales 
  

   are 
  finely 
  exposed, 
  dipping 
  steeply 
  to 
  the 
  westward 
  and 
  unconform- 
  

   ably 
  overlaid 
  by 
  Helderberg 
  beds 
  which 
  give 
  rise 
  to 
  cliffs 
  above. 
  

   A 
  mile 
  below 
  the 
  fault 
  the 
  dip 
  flattens 
  considerably 
  and 
  in 
  the 
  

   center 
  and 
  eastern 
  limb 
  of 
  this 
  gentle 
  synclinal 
  of 
  Helderberg 
  

   limestones 
  at 
  the 
  road 
  metal 
  quarry 
  there 
  is 
  nearly 
  perfect 
  con- 
  

   formity 
  between 
  Hudson 
  river 
  sandstones 
  and 
  shales 
  and 
  the 
  

   overlying 
  limestones. 
  This 
  is 
  only 
  a 
  local 
  coincidence, 
  however, 
  

   for 
  to 
  the 
  southeastward 
  along 
  the 
  face 
  of 
  the 
  Helderberg 
  

   escarpment 
  there 
  is 
  marked 
  unconformity 
  in 
  the 
  district 
  west 
  of 
  

   Coeymans. 
  

  

  In 
  this 
  section 
  on 
  the 
  plate 
  the 
  structure 
  of 
  the 
  Hudson 
  river 
  

   rocks 
  to 
  the 
  eastward 
  is 
  also 
  shown, 
  but 
  this 
  is 
  intended 
  to 
  

   afford 
  only 
  an 
  idea 
  of 
  the 
  general 
  features 
  of 
  the 
  flexures, 
  for 
  

   owing 
  to 
  the 
  heavy 
  drift 
  cover 
  I 
  was 
  unable 
  to 
  ascertain 
  the 
  

   details. 
  

  

  Along' 
  the 
  Hudson 
  valley 
  northward 
  to 
  Albany 
  and 
  beyond, 
  

   the 
  Hudson 
  river 
  rocks 
  are 
  steeply 
  folded, 
  probably 
  also 
  faulted 
  

   and 
  have 
  an 
  exceedingly 
  complicated 
  structure. 
  Owing 
  to 
  the 
  

   lack 
  of 
  distinct 
  stratigraphy 
  in 
  the 
  beds 
  involved, 
  to 
  the 
  rarity 
  

   of 
  extensive 
  outcrops 
  across 
  the 
  strike, 
  and 
  to 
  the 
  extreme 
  contor- 
  

   tion 
  at 
  all 
  points, 
  I 
  was 
  unable, 
  in 
  the 
  time 
  at 
  my 
  disposal, 
  to 
  

   work 
  out 
  the 
  structure 
  of 
  the 
  region. 
  The 
  contortion 
  of 
  the 
  

   beds 
  is 
  exposed 
  at 
  many 
  points 
  near 
  Albany, 
  noticeably 
  along 
  the 
  

   Norman's 
  Kill 
  near 
  Kenwood, 
  and 
  southward 
  along 
  the 
  West 
  Shore 
  

   railroad 
  from 
  " 
  The 
  Abbey 
  " 
  to 
  Wemple. 
  Along 
  the 
  Mohawk 
  river 
  

   there 
  are 
  many 
  exposures 
  of 
  the 
  flexed 
  Hudson 
  river 
  beds. 
  To 
  the 
  

   westward 
  the 
  flexures 
  are 
  gentle, 
  but 
  their 
  steepness 
  increases 
  

   rapidly 
  to 
  the 
  eastward, 
  and 
  at 
  the 
  great 
  exposures 
  at 
  Cohoes 
  

   falls 
  the 
  beds 
  are 
  seen 
  to 
  be 
  steeply 
  flexed 
  and 
  much 
  contorted. 
  

  

  