﻿

  Report 
  of 
  the 
  State 
  Geologist, 
  409 
  

  

  of 
  the 
  village. 
  Its 
  thickness 
  decreases 
  southward 
  toward 
  Ellen- 
  

   ville. 
  The 
  Pentamerus 
  beds 
  are 
  quite 
  sharply 
  demarked 
  from 
  

   adjoining 
  beds, 
  a 
  few 
  inches 
  of 
  passage 
  beds 
  intervening. 
  

  

  The 
  finest 
  exposures 
  of 
  the 
  Pentamerus 
  ledges 
  are 
  in 
  the 
  great 
  

   escarpment 
  of 
  the 
  Helderberg 
  mountains, 
  near 
  the 
  Indian 
  Ladder 
  

   where 
  they 
  rise 
  in 
  great 
  cliffs 
  surmounting 
  steep 
  slopes 
  to 
  an 
  

   altitude 
  of 
  TOO 
  feet 
  above 
  the 
  plain 
  lying 
  to 
  the 
  north 
  and 
  east. 
  

   The 
  cliffs 
  on 
  the 
  eastern 
  slope 
  of 
  the 
  West 
  mountain, 
  opposite 
  

   Schoharie, 
  are 
  also 
  very 
  imposing, 
  as 
  may 
  be 
  seen 
  in 
  some 
  

   measure 
  in 
  the 
  illustrated 
  figure 
  4. 
  

  

  The 
  Tentaculite 
  beds 
  are 
  thin-bedded 
  dark-blue 
  limestones, 
  

   lying 
  below 
  the 
  Pentamerus 
  beds, 
  and 
  usually 
  constituting 
  the 
  

   base 
  of 
  the 
  Pentamerus 
  escarpment 
  or 
  lying 
  beneath 
  its 
  talus. 
  

   The 
  beds 
  vary 
  in 
  thickness 
  from 
  an 
  inch 
  to 
  a 
  foot 
  in 
  greater 
  part, 
  

   but 
  two 
  or 
  three 
  inches 
  is 
  the 
  general 
  average. 
  Some 
  inter- 
  

   calated 
  shaly 
  layers 
  are 
  sometimes 
  noticeable. 
  In 
  the 
  upper 
  

   members 
  there 
  is 
  a 
  thin 
  sub-bedding, 
  indicated 
  by 
  a 
  ribboning 
  of 
  

   alternating 
  lighter 
  and 
  darker 
  tints, 
  constituting 
  the 
  " 
  Ribbon 
  

   limestone" 
  of 
  some 
  writers. 
  Just 
  below 
  this 
  ribboned 
  series 
  

   there 
  is 
  usually 
  a 
  thin 
  bed 
  of 
  Stromatopora, 
  which 
  characterizes 
  

   this 
  horizon. 
  The 
  Tentaculite 
  beds 
  have 
  a 
  thickness 
  of 
  forty 
  feet 
  

   at 
  Howe's 
  Cave 
  and 
  Schoharie, 
  somewhat 
  less 
  in 
  the 
  Helderberg 
  

   mountains, 
  and 
  from 
  thirty 
  to 
  forty 
  feet 
  through 
  the 
  Catskill 
  and 
  

   Kingston 
  regions. 
  In 
  the 
  Eosendale 
  region 
  the 
  amount 
  is 
  less. 
  

   Some 
  features 
  of 
  the 
  Tentaculite 
  beds 
  are 
  illustrated 
  in 
  figures 
  

   3 
  and 
  4. 
  

  

  There 
  are 
  several 
  outliers 
  of 
  the 
  Helderberg 
  limestone 
  which 
  

   are 
  of 
  great 
  interest 
  as 
  indications 
  of 
  the 
  original 
  extent 
  of 
  the 
  

   formation. 
  One 
  of 
  the 
  most 
  noteworthy 
  outliers 
  is 
  on 
  Becraft's 
  

   mountain 
  a 
  short 
  distance 
  southeast 
  of 
  Hudson, 
  which 
  has 
  been 
  

   described 
  in 
  detail 
  by 
  Davis.* 
  It 
  is 
  a 
  small, 
  shallow, 
  oblong 
  

   synclinal 
  area 
  covering 
  about 
  two 
  square 
  miles 
  and 
  exhibiting 
  

   Tentaculite, 
  Pentamerus, 
  lower 
  Shaly 
  and 
  Becraft 
  beds, 
  together 
  

   with 
  Oriskany, 
  Esopus 
  shale 
  and 
  a 
  very 
  small 
  outlier 
  of 
  Onon- 
  

   daga 
  limestone 
  before 
  referred 
  to. 
  The 
  Tentaculite 
  beds 
  are 
  

   described 
  as 
  fine, 
  blue, 
  even, 
  thin 
  beds, 
  weathering 
  light 
  colored 
  

   and 
  smooth 
  and 
  having 
  a 
  thickness 
  of 
  twenty 
  to 
  thirty 
  feet. 
  

  

  * 
  Becraft's 
  mountain; 
  Am. 
  Jour. 
  Sci., 
  3d 
  series, 
  toI. 
  26, 
  pp. 
  381-389. 
  1883. 
  

  

  52 
  

  

  