﻿I06 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  Hydraulic 
  cement 
  beds, 
  i) 
  The 
  lowest 
  stratum 
  of 
  the 
  series 
  is 
  a 
  

   hard, 
  compact, 
  bluish 
  gray 
  silicious 
  limestone, 
  weathering 
  whitish 
  

   on 
  the 
  exposed 
  faces, 
  and 
  breaking 
  into 
  numerous 
  irregular 
  frag- 
  

   ments 
  larger 
  near 
  the 
  bottom 
  of 
  the 
  stratum 
  but 
  becoming 
  small, 
  

   angular 
  and 
  subcubical 
  near 
  the 
  top, 
  where 
  the 
  weathering 
  is 
  

   similar 
  to 
  that 
  obtaining 
  in 
  the 
  upper 
  parts 
  of 
  the 
  shales. 
  This 
  

   stratum 
  varies 
  from 
  7 
  to 
  8 
  feet 
  in 
  thickness 
  being 
  in 
  places 
  divided 
  

   into 
  two 
  tiers, 
  the 
  upper 
  one, 
  4 
  feet 
  thick, 
  appearing 
  as 
  a 
  distinct 
  

   bed. 
  This 
  weathers 
  to 
  a 
  creamy 
  gray 
  color, 
  and 
  breaks 
  into 
  small 
  

   angular 
  fragments 
  with 
  no 
  regularity 
  of 
  fracture, 
  and 
  independent 
  of 
  

   the 
  plane 
  of 
  stratification. 
  On 
  some 
  of 
  the 
  weathered 
  edges 
  of 
  this 
  

   rock 
  irregular 
  stratification 
  lines 
  are 
  visible, 
  giving 
  the 
  beds 
  the 
  

   appearance 
  of 
  a 
  fine 
  grained 
  sandstone. 
  Occasionally 
  small 
  geoditic 
  

   cavities 
  occur 
  lined 
  with 
  dolomite 
  or 
  gypsum. 
  The 
  line 
  of 
  contact 
  

   between 
  this 
  stratum 
  and 
  the 
  underlying 
  shale 
  is 
  an 
  irregular 
  one, 
  

   the 
  shale 
  surface 
  having 
  a 
  wavy 
  character. 
  

  

  2) 
  This 
  rock 
  is 
  succeeded 
  by 
  a 
  4 
  foot 
  stratum 
  of 
  arenaceous 
  lime- 
  

   stone 
  which 
  shows 
  no 
  well 
  marked 
  stratification 
  lines 
  on 
  the 
  

   weathered 
  surfaces, 
  though 
  in 
  places 
  a 
  distinct 
  cross-bedding 
  struc- 
  

   ture 
  appears. 
  It 
  peels 
  off 
  in 
  irregular 
  slabs 
  parallel 
  to 
  the 
  cross- 
  

   section, 
  i. 
  e. 
  at 
  right 
  angles 
  to 
  the 
  stratification 
  plane. 
  Near 
  the 
  top 
  

   of 
  this 
  stratum 
  are 
  a 
  few 
  thin 
  beds 
  which 
  show 
  the 
  finer 
  stratification 
  

   structure 
  on 
  the 
  weathered 
  edges, 
  the 
  character 
  of 
  this 
  structure 
  

   being 
  such 
  as 
  is 
  found 
  in 
  fine 
  grained 
  sandstones. 
  

  

  Both 
  these 
  strata 
  appear 
  to 
  be 
  wholly 
  destitute 
  of 
  fossils., 
  It 
  is 
  

   not 
  improbable 
  however 
  that 
  the 
  scattered 
  geodes 
  represent 
  the 
  

   places 
  where 
  corals 
  or 
  crinoids 
  occurred, 
  which 
  have 
  subsequently 
  

   been 
  altered 
  or 
  dissolved 
  out. 
  Aside 
  from 
  this, 
  there 
  is 
  no 
  evidence 
  

   that 
  this 
  rock 
  ever 
  was 
  fossiliferous, 
  and 
  it 
  is 
  most 
  probable 
  that 
  it 
  

   represents 
  the 
  accumulation 
  of 
  fine 
  calcareous 
  mud 
  or 
  sand. 
  

  

  Crinoidal 
  limestone. 
  3) 
  The 
  compact 
  hydraulic 
  rock 
  is 
  abruptly 
  

   succeeded 
  by 
  a 
  stratum 
  of 
  highly 
  crystalline 
  limestone, 
  on 
  the 
  

   weathered 
  surfaces 
  of 
  which 
  joints 
  of 
  crinoid 
  stems 
  and 
  other 
  organ- 
  

   isms 
  stand 
  out 
  in 
  relief, 
  particularly 
  in 
  the 
  lower 
  part 
  of 
  the 
  stratum. 
  

   The 
  rock 
  is 
  entirely 
  composed 
  of 
  fragments 
  of 
  organisms 
  which 
  were 
  

   ground 
  up 
  and 
  mingled 
  together 
  in 
  great 
  profusion. 
  Oblique 
  

  

  