﻿432 
  Forty-seventh 
  Report 
  on 
  the 
  State 
  Museum, 
  

  

  The 
  rocks 
  in 
  Albany 
  county 
  are 
  the 
  Hudson 
  river 
  slates 
  and 
  

   sandstones, 
  and 
  members 
  of 
  the 
  upper 
  Silurian 
  and. 
  Devonian 
  

   from 
  the 
  Salina 
  to 
  the 
  Oneonta. 
  They 
  are 
  as 
  follows 
  : 
  

  

  Thickness. 
  

   Feet. 
  

  

  Oneonta, 
  red 
  shales 
  and 
  flaggy 
  sandstones 
  1000 
  

  

  Hamilton 
  flags 
  and 
  shales 
  700 
  

  

  Hamilton 
  black 
  shales 
  600 
  

  

  Onondaga 
  limestone 
  70 
  

  

  Schoharie 
  grit 
  6 
  

  

  Esopus 
  shales 
  100 
  

  

  Oriskany 
  sandstone 
  . 
  . 
  . 
  , 
  4 
  

  

  Becraft 
  limestone 
  15 
  

  

  Shaly 
  limestone 
  100 
  

  

  Pentamerus 
  limestone 
  . 
  65 
  

  

  Tentaculite 
  limestone 
  30 
  

  

  Salina 
  waterlime 
  • 
  4 
  

  

  Hudson 
  river 
  shales 
  and 
  sandstone 
  3500 
  

  

  P 
  There 
  are 
  also 
  wide 
  areas 
  of 
  sand 
  and 
  clay 
  and 
  many 
  deposits 
  

   of 
  glacial 
  drift. 
  The 
  Oneida, 
  Medina, 
  Clinton 
  and 
  Niagara 
  

   formations 
  are 
  lacking, 
  possibly 
  the 
  Niagara 
  formation 
  exists 
  at 
  

   some 
  points 
  in 
  the 
  base 
  of 
  the 
  Helderberg 
  escarpment 
  under 
  the 
  

   drift 
  and 
  talus. 
  

  

  Oneonta 
  formation. 
  — 
  This 
  formation 
  has 
  not 
  before 
  been 
  

   differentiated 
  in 
  Albany 
  county, 
  but 
  I 
  have 
  traced 
  it 
  continuously 
  

   from 
  the 
  typical 
  region 
  eastward 
  and 
  find 
  that 
  it 
  is 
  extensively 
  

   developed. 
  It 
  consists 
  of 
  a 
  series 
  of 
  flaggy 
  sandstones 
  with 
  

   intercalations 
  of 
  red 
  shales 
  which 
  cover 
  the 
  elevated 
  regions 
  of 
  

   the 
  southwestern 
  corner 
  of 
  the 
  countv 
  in 
  Rensselaerville 
  and 
  

   Westerlo 
  townships. 
  It 
  is 
  cu£ 
  through 
  by 
  the 
  valley 
  of 
  Ten- 
  

   Mile 
  creek, 
  which 
  separates 
  the 
  high 
  regions 
  west 
  and 
  south 
  of 
  

   Rensselaerville. 
  The 
  red 
  shales 
  are 
  a 
  conspicuous 
  feature 
  of 
  the 
  

   formation 
  and 
  are 
  extensively 
  exposed 
  throughout 
  its 
  area. 
  

   They 
  constitute 
  beds 
  of 
  from 
  one 
  to 
  thirty 
  feet 
  in 
  thickness, 
  

   intercalated 
  at 
  irregular 
  intervals 
  among 
  dark-gray, 
  flaggy 
  

   sandstones. 
  There 
  are 
  also 
  in 
  the 
  formation, 
  beds 
  of 
  red 
  sand- 
  

   stone 
  ard 
  thin 
  beds 
  of 
  dark-gray 
  or 
  black 
  shales, 
  but 
  they 
  are 
  

   of 
  infrequent 
  occurrence 
  and 
  of 
  no 
  great 
  thickness. 
  The 
  beds 
  

   of 
  red 
  [shale 
  appear 
  to 
  be 
  continuous 
  over 
  wide 
  areas, 
  but 
  in 
  

  

  