﻿Report 
  of 
  the 
  State 
  Geologist. 
  435 
  

  

  hill. 
  The 
  beds 
  of 
  flags 
  are 
  not 
  at 
  any 
  definite 
  horizon, 
  although 
  

   the 
  greater^amount 
  of 
  flag 
  which 
  has 
  been 
  worked 
  is 
  from 
  beds 
  

   about 
  250 
  feet 
  above 
  the 
  base 
  of 
  the 
  series. 
  The 
  principal 
  

   quarries 
  are 
  between 
  Kensselaerville 
  and 
  South 
  Berne, 
  at 
  Keids- 
  

   vflle 
  and 
  at 
  Dormansville. 
  There 
  are 
  many 
  small 
  quarries 
  

   scattered 
  about 
  at 
  various 
  localities. 
  The 
  quarries 
  between 
  

   Kensselaerville 
  and 
  South 
  Berne 
  are 
  in 
  a 
  bed 
  about 
  twelve 
  feet 
  

   thick, 
  which 
  is 
  relatively 
  uniform 
  in 
  character 
  throughout, 
  and 
  

   has 
  yielded 
  a 
  valuable 
  product. 
  The 
  Eeidsville 
  quarries 
  have 
  

   been 
  worked 
  in 
  several 
  beds, 
  constituting 
  a 
  local 
  series, 
  about 
  

   twenty-five 
  feet 
  thick. 
  The 
  Dormansville 
  quarries 
  are 
  in 
  a 
  bed 
  

   about 
  ten 
  feet 
  thick, 
  which 
  yielded 
  a 
  very 
  large 
  amount 
  of 
  

   excellent 
  flagging. 
  The 
  region 
  occupied 
  by 
  the 
  flag 
  series 
  is 
  

   deeply 
  trenched 
  by 
  the 
  Switzkill, 
  which 
  cuts 
  through 
  into 
  the 
  

   underlying 
  shales. 
  It 
  extends 
  southward 
  into 
  Greene 
  county 
  

   and 
  the 
  deep 
  valley 
  of 
  Ten-Mile 
  run 
  and 
  are 
  finely 
  exposed 
  at 
  the 
  

   falls 
  at 
  Kensselaerville 
  and 
  end 
  in 
  the 
  gorge 
  above. 
  They 
  are 
  

   widely 
  removed 
  in 
  the 
  regicn 
  adjacent 
  to 
  the 
  Hannacrois 
  

   creek, 
  but 
  there 
  are 
  outliers 
  along 
  ihe 
  higher 
  summits 
  of 
  

   the 
  Helderberg 
  mountains, 
  in 
  the 
  high 
  area 
  west 
  of 
  Country- 
  

   man 
  hill, 
  and 
  in 
  the 
  higher 
  summits 
  of 
  Koong 
  and 
  Blodgett 
  hills, 
  

   which 
  all 
  appear 
  to 
  belong 
  to 
  this 
  series. 
  The 
  basal 
  line 
  of 
  

   the 
  formation 
  has 
  been 
  drawn 
  at 
  the 
  bottom 
  of 
  the 
  lowest 
  heavy 
  

   bed 
  of 
  flags 
  which 
  appears 
  to 
  be 
  a 
  relatively 
  constant 
  horizon 
  

   over 
  a 
  wide 
  area, 
  although 
  its 
  stratigraphic 
  position 
  may 
  vary 
  

   somewhat. 
  The 
  thickness 
  of 
  the 
  series 
  is 
  about 
  TOO 
  feet. 
  It 
  dips 
  

   south-southwest 
  in 
  Berne 
  township, 
  and 
  to 
  the 
  southwest 
  in 
  

   "Westerlo 
  township. 
  There 
  are 
  local 
  variations 
  in 
  the 
  direction 
  and 
  

   amount 
  of 
  dip 
  but 
  they 
  were 
  not 
  studied 
  in 
  detail. 
  

  

  The 
  lower 
  portion 
  of 
  the 
  formation 
  is 
  sparingly 
  fossiliferous, 
  

   particularly 
  some 
  of 
  the 
  softer 
  thinner 
  flags, 
  which 
  yield 
  a 
  

   Hamilton 
  group 
  fauna. 
  The 
  upper 
  beds 
  of 
  the 
  series 
  may 
  extend 
  

   above 
  the 
  limits 
  of 
  the 
  Hamilton 
  group 
  of 
  western 
  New 
  York, 
  

   but 
  I 
  have 
  at 
  present 
  no 
  definite 
  evidence 
  on 
  this 
  point. 
  

  

  The 
  Hamilton 
  black 
  shales. 
  — 
  This 
  formation 
  comprises 
  600 
  

   feet 
  of 
  argillaceous 
  deposits 
  lying 
  between 
  the 
  flagstone 
  

   series 
  and 
  the 
  Onondaga 
  limestone. 
  It 
  constitutes 
  the 
  steep 
  

   northern 
  and 
  eastern 
  slopes 
  south 
  and 
  west 
  of 
  the 
  Helderberg 
  

  

  