﻿Report 
  of 
  the 
  State 
  Geologist. 
  439 
  

  

  feature 
  not 
  unusual 
  near 
  the 
  upper 
  part 
  of 
  the 
  formation. 
  The 
  

   finest 
  exposures 
  that 
  I 
  have 
  seen 
  of 
  this 
  stratum 
  are 
  at 
  Clarks- 
  

   ville 
  in 
  a 
  small 
  inlayiDg 
  area 
  exposed 
  in 
  the 
  stream 
  cut 
  just 
  south 
  

   of 
  the 
  center 
  of 
  the 
  village. 
  

  

  Oriskany 
  sandstone. 
  — 
  This 
  is 
  a 
  very 
  thin 
  bed 
  of 
  hard 
  sand- 
  

   stone 
  or 
  quartzite 
  which 
  is 
  continuous 
  over 
  a 
  wide 
  area. 
  Owing 
  

   to 
  its 
  hardness 
  it 
  usually 
  gives 
  rise 
  to 
  an 
  outcrop 
  of 
  considerable 
  

   width 
  constituting 
  a 
  well-defined 
  shelf, 
  at 
  the 
  base 
  01 
  the 
  slopes 
  

   of 
  Esopus 
  shale. 
  This 
  shelf 
  bears 
  in 
  some 
  parts 
  of 
  the 
  area 
  

   masses 
  of 
  glacial 
  drift 
  and 
  the 
  formation 
  is 
  completely 
  hidden 
  by 
  

   this 
  material 
  near 
  the 
  western 
  margin 
  of 
  the 
  county 
  and 
  at 
  

   several 
  points 
  in 
  the 
  Oniskethau 
  valley. 
  Between 
  Knox 
  and 
  

   Indian 
  Ladder 
  the 
  formation 
  affords 
  a 
  hard, 
  even 
  bed 
  for 
  the 
  roads 
  

   for 
  considerable 
  distances, 
  and 
  its 
  exposures 
  along 
  these 
  roads 
  

   are 
  very 
  characteristic. 
  Tor 
  several 
  miles 
  south 
  from 
  Callanans 
  

   Corners 
  the 
  formation 
  appears 
  to 
  be 
  absent, 
  as 
  several 
  exposures 
  

   were 
  examined 
  in 
  which 
  the 
  Esopus 
  shales 
  appeared 
  to 
  lie 
  directly 
  

   on 
  the 
  Becraft 
  limestone. 
  It 
  comes 
  in 
  again 
  wQst 
  of 
  Coeymans 
  

   Junction, 
  where 
  it 
  is 
  exposed 
  at 
  several 
  points 
  at 
  the 
  base 
  of 
  the 
  

   easternmost 
  ridge 
  of 
  Esopus 
  shales. 
  The 
  formation 
  is 
  in 
  greater 
  

   part 
  calcareous, 
  but 
  the 
  amount 
  of 
  lime 
  which 
  it 
  contains 
  is 
  varia- 
  

   ble. 
  Usually 
  there 
  are 
  beds 
  which 
  are 
  very 
  calcareous 
  and 
  

   weather 
  to 
  a 
  porous 
  buff 
  sandrock 
  filled 
  with 
  characteristic 
  casts 
  

   of 
  the 
  fossils 
  ; 
  and 
  these 
  are 
  conspicuous 
  in 
  nearly 
  every 
  exposure. 
  

   The 
  thickness 
  varies 
  from 
  one 
  to 
  four 
  feet 
  and 
  averages 
  about 
  

   three 
  feet 
  over 
  the 
  greater 
  part 
  of 
  the 
  area. 
  

  

  Becraft 
  limestone. 
  — 
  This 
  is 
  the 
  uppermost 
  member 
  of 
  the 
  Helder- 
  

   berg 
  limest 
  mes. 
  It 
  is 
  a 
  light-colored, 
  coarsely 
  semi-crystalline 
  rock 
  

   in 
  thick 
  beds. 
  It 
  is 
  highly 
  fossiliferous, 
  consisting 
  in 
  considerable 
  

   part 
  of 
  replacements 
  of 
  fossils. 
  The 
  most 
  conspicuous 
  of 
  these 
  

   are 
  the 
  cups 
  or 
  pelves 
  of 
  a 
  crinoid, 
  having 
  in 
  greater 
  part 
  a 
  diam- 
  

   eter 
  of 
  from 
  one 
  to 
  two 
  inches. 
  The 
  white 
  calcite 
  by 
  which 
  these 
  

   remains 
  are 
  now 
  represented 
  contrasts 
  strongly 
  with 
  the 
  light 
  

   bluish-grav 
  of 
  the 
  containing 
  limestone 
  and 
  are 
  a 
  distinguishing 
  

   feature 
  throughout. 
  Its 
  thickness 
  averages 
  about 
  fifteen 
  feet, 
  

   but 
  at 
  some 
  points 
  it 
  appears 
  to 
  be 
  slightly 
  less. 
  It 
  usually 
  gives 
  

   rise 
  to 
  a 
  low 
  cliff 
  capped 
  by 
  the 
  Oriskany 
  sandstone 
  ; 
  its 
  finest 
  

   exposures 
  are 
  in 
  the 
  vicinity 
  of 
  Knox, 
  but 
  it 
  is 
  also 
  frequently 
  

  

  