﻿LIMESTONES 
  OF 
  NEW 
  YORK 
  AND 
  THEIR 
  ECONOMIC 
  VALUE 
  367 
  

  

  Iu 
  Greene 
  and 
  Ulster 
  counties 
  particularly 
  the 
  outcropping 
  

   edge 
  of 
  the 
  formation 
  is 
  characterized 
  by 
  a 
  fringe 
  of 
  very 
  large 
  

   disconnected 
  blocks 
  occurring 
  at 
  various 
  intervals. 
  In 
  some 
  

   cases 
  these 
  blocks 
  lie 
  several 
  hundred 
  yards 
  from 
  the 
  edge 
  of 
  the 
  

   outcrop. 
  

  

  Helderberg 
  limestones. 
  The 
  members 
  comprised 
  under 
  this 
  

   name 
  are 
  the 
  Upper 
  shaly 
  beds, 
  the 
  Scutella 
  or 
  Upper 
  Pentam- 
  

   erus 
  beds, 
  the 
  Lower 
  shaly 
  or 
  Catskill 
  shaly 
  beds, 
  the 
  Pentam- 
  

   erus 
  beds 
  and 
  the 
  Tentaculite 
  beds. 
  These 
  members 
  preserve 
  

   their 
  distinctive 
  characters 
  throughout 
  the 
  region 
  to 
  which 
  the 
  

   report 
  relates 
  though 
  there 
  are 
  occasional 
  slight 
  local 
  variations. 
  

  

  The 
  so-called 
  Scutella 
  beds 
  are 
  the 
  uppermost 
  member 
  south- 
  

   ward 
  to 
  near 
  Catskill. 
  They 
  are 
  light 
  colored 
  coarsely 
  semi- 
  

   crystalline 
  massive 
  bedded, 
  highly 
  fossiliferous 
  limestone 
  

   blotched 
  with 
  calcite 
  replacement 
  of 
  fossils, 
  of 
  which 
  the 
  most 
  

   conspicuous 
  is 
  the 
  so-called 
  Scutella. 
  These 
  are 
  the 
  cups 
  or 
  pelvis 
  

   of 
  a 
  crinoid, 
  having 
  a 
  diameter 
  in 
  greater 
  part 
  from 
  one 
  to 
  two 
  

   inches, 
  and 
  the 
  white 
  calcite 
  of 
  which 
  they 
  consist 
  contrasts 
  

   strongly 
  with 
  the 
  light 
  bluish 
  gray 
  of 
  the 
  containing 
  limestone. 
  

   In 
  the 
  Schoharie 
  region 
  where 
  these 
  cups 
  characterize 
  the 
  lower 
  

   beds 
  of 
  the 
  member, 
  the 
  overlying 
  layers 
  have 
  been 
  called 
  the 
  

   upper 
  Pentamerus 
  beds 
  from 
  the 
  fossil 
  P. 
  pseudogaleatus 
  which 
  

   they 
  contain 
  and 
  this 
  name 
  has 
  been 
  employed 
  to 
  some 
  extent 
  

   to 
  comprise 
  all 
  the 
  beds. 
  In 
  the 
  eastern 
  extension 
  of 
  the 
  

   formation 
  the 
  distinction 
  is 
  lost. 
  About 
  Catskill, 
  Davis 
  desig- 
  

   nates 
  the 
  lower, 
  layers 
  the 
  " 
  Encrinal 
  " 
  and 
  the 
  upper 
  layers 
  the 
  

   " 
  Upper 
  Pentamerus 
  " 
  limestone. 
  Owing 
  to 
  the 
  inappropriate- 
  

   ness 
  of 
  the. 
  name 
  Scutella 
  and 
  the 
  varying 
  significance 
  of 
  the 
  

   other 
  names 
  that 
  have 
  been 
  employed, 
  the 
  geographic 
  name 
  of 
  

   Becraft 
  limestone 
  has 
  been 
  suggested 
  by 
  Prof. 
  Hall. 
  The 
  

   name 
  is 
  from 
  Becraft 
  mountain 
  in 
  Columbia 
  co. 
  where 
  the 
  

   rock 
  is 
  typically 
  developed. 
  The 
  Becraft 
  limestone 
  has 
  a 
  thick- 
  

   ness 
  of 
  10 
  to 
  15 
  feet 
  near 
  Schoharie 
  and 
  the 
  amount 
  does 
  not 
  

   vary 
  greatly 
  eastward 
  to 
  the 
  Helderberg 
  mountains 
  and 
  by 
  

   Clarksvilld, 
  Aquetuck 
  and 
  Coxsackie. 
  Thence 
  it 
  increases 
  

   rapidly 
  and 
  Davis 
  reports 
  a 
  thickness 
  of 
  120 
  feet 
  below 
  Leeds, 
  

  

  