﻿44(5 
  Forty- 
  seventh 
  Report 
  on 
  the 
  State 
  Museum. 
  

  

  In 
  section 
  I 
  the 
  amount 
  of 
  dip 
  appears 
  to 
  be 
  not 
  over 
  100 
  feet 
  to 
  a 
  

   mile. 
  Here 
  the 
  Onondaga 
  limestone 
  is 
  bared 
  over 
  a 
  wide 
  area, 
  and 
  

   the 
  underlying 
  formations 
  outcrop 
  in 
  succession 
  northward 
  in 
  broad 
  

   terraces. 
  They 
  are, 
  however, 
  heavily 
  drift 
  covered 
  and 
  there 
  are 
  

   too 
  few 
  outcrops 
  on 
  which 
  to 
  base 
  a 
  satisfactory 
  determination 
  

   of 
  structure. 
  In 
  section 
  II, 
  the 
  dip 
  is 
  about 
  the 
  same 
  or 
  slightly 
  

   less 
  and 
  the 
  Hamilton 
  shales 
  are 
  seen 
  extending 
  to 
  within 
  a 
  mile 
  

   of 
  the 
  Helderberg 
  escarpment, 
  with 
  the 
  underlying 
  formations 
  

   occupying 
  narrow 
  belts 
  in 
  the 
  slopes 
  below. 
  To 
  the 
  eastward 
  

   about 
  Thompson's 
  lake 
  and 
  Indian 
  Ladder 
  the 
  dip 
  is 
  reduced 
  to 
  an 
  

   amount 
  not 
  over 
  thirty-five 
  feet 
  per 
  mile, 
  but 
  there 
  is 
  some 
  evi- 
  

   dence 
  that 
  it 
  is 
  more 
  variable 
  in 
  this 
  section 
  than 
  it 
  is 
  to 
  the 
  west- 
  

   ward. 
  The 
  following 
  figure 
  is 
  along 
  the 
  eastern 
  face 
  of 
  the 
  

   Helderberg 
  mountains 
  and 
  exhibits 
  the 
  structure 
  of 
  this 
  great 
  

   escarpment, 
  which 
  is 
  such 
  a 
  conspicuous 
  feature 
  in 
  Albany 
  county. 
  

   In 
  this 
  vicinit}^ 
  the 
  southerly 
  dip 
  gradually 
  changes 
  to 
  the 
  south- 
  

   westward 
  and 
  decreases 
  in 
  amount. 
  

  

  

  F 
  'S 
  

  

  Fig. 
  3— 
  Section 
  along 
  the 
  eastern 
  face 
  of 
  Helderberg 
  mountains, 
  in 
  the 
  vicinity 
  of 
  New 
  

   Salem. 
  Scales: 
  Vertical, 
  1600 
  feet 
  to 
  one 
  inch; 
  horizontal, 
  4000 
  feet 
  to 
  one 
  inch; 
  H., 
  Hamilton; 
  

   On., 
  'Onondaga 
  limestone; 
  CGr 
  , 
  Esopus 
  shales; 
  Or., 
  Oriskany; 
  Sc, 
  Becraft 
  limestone; 
  Si 
  , 
  Shaly 
  

   limestone; 
  P., 
  Pentamerus 
  limestone; 
  T., 
  TentacuLte 
  beds 
  and 
  Salina 
  waterlime. 
  Looking 
  

   west. 
  

  

  The 
  succession 
  of 
  rocks 
  is 
  superbly 
  exposed 
  in 
  the 
  eastern 
  

   face 
  of 
  this 
  great 
  escarpment 
  as 
  a 
  series 
  of 
  terraces, 
  from 
  the 
  

   Hamilton 
  at 
  the 
  top, 
  to 
  the 
  long 
  slopes 
  of 
  Hudson 
  river 
  shales 
  

   and 
  sandstones 
  below 
  ; 
  the 
  principal 
  terrace 
  scarps 
  being 
  marked 
  

   by 
  the 
  Onondaga 
  limestone, 
  Oriskany 
  sandstone, 
  and 
  Pentamerus 
  

   limestone 
  with 
  adjoining 
  formations 
  in 
  the 
  intervening 
  slopes. 
  

   The 
  dip 
  averages 
  112 
  feet 
  per 
  mile 
  and 
  south 
  ten 
  degrees 
  west 
  in 
  

   direction. 
  This 
  carries 
  the 
  outcropping 
  edges 
  of 
  the 
  formation 
  

   gradually 
  downward 
  along 
  the 
  face 
  of 
  the 
  mountain, 
  from 
  an 
  

   altitude 
  of 
  1100 
  feet 
  above 
  tide 
  south 
  of 
  Altamont 
  to 
  about 
  1000 
  

   at 
  Indian 
  Ladder 
  and 
  66v 
  feet 
  a 
  mile 
  south 
  of 
  New 
  Salem. 
  To 
  the 
  

  

  