﻿Il8 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  ably 
  on 
  the 
  former, 
  this 
  unconformity 
  being 
  emphasized 
  by 
  the 
  

   absence 
  of 
  all 
  Lower 
  Devonic 
  strata 
  in 
  this 
  region, 
  with 
  the 
  excep- 
  

   tion 
  of 
  thin 
  lenses 
  of 
  sandstone 
  which 
  may 
  be 
  correlated 
  with 
  the 
  

   Oriskany. 
  The 
  upper 
  surface 
  of 
  the 
  Manlius 
  limestone 
  is 
  knotty 
  

   and 
  concretionary, 
  producing 
  minor 
  irregularities, 
  but 
  in 
  addition 
  

   to 
  these 
  there 
  are 
  well 
  marked 
  traces 
  of 
  the 
  erosion 
  of 
  these 
  strata, 
  

   prior 
  to 
  the 
  deposition 
  of 
  the 
  overlying 
  beds. 
  These 
  traces 
  are 
  of 
  the 
  

   nature 
  of 
  channels 
  and 
  irregular 
  truncations 
  of 
  the 
  strata, 
  the 
  former 
  

   in 
  some 
  cases 
  assuming 
  considerable 
  importance. 
  (Fig. 
  21-23) 
  

  

  In 
  the 
  east 
  wall 
  of 
  the 
  quarry, 
  

   not 
  far 
  from 
  the 
  stamp 
  mill, 
  

   the 
  surface 
  of 
  the 
  Manlius 
  

   limestone 
  is 
  strongly 
  ex- 
  

  

  Fig. 
  21 
  Unconformable 
  contact 
  between 
  Manlius 
  ppvatprl 
  the 
  pvravpitinn 
  heincr 
  

   and 
  Onondaga 
  limestones, 
  Buffalo 
  cement 
  quarry. 
  *-^Vdieu, 
  Clie 
  eXLdVdllun 
  ueiHj^ 
  

  

  mainly 
  filled 
  by 
  beds 
  of 
  the 
  

   Onondaga 
  limestone. 
  Be- 
  

   tween 
  the 
  two 
  limestones 
  oc- 
  

   curs 
  a 
  mass 
  of 
  shale 
  and 
  

  

  Fig. 
  22 
  Erosion 
  Of 
  Manlius 
  limestone 
  prior 
  to 
  deposi- 
  Conglomerate 
  having 
  a 
  total 
  

   tlon 
  of 
  Onondaga 
  limestone, 
  Buffalo 
  cement 
  quarry. 
  ,1-1 
  . 
  , 
  1 
  ,1 
  

  

  thickness, 
  m 
  the 
  central 
  por- 
  

   tion, 
  of 
  something 
  over 
  a 
  foot. 
  The 
  lower 
  6 
  or 
  8 
  inches 
  are 
  a 
  lime- 
  

   stone 
  conglomerate, 
  the 
  pebbles 
  of 
  which 
  are 
  fragments 
  of 
  the 
  

   underlying 
  limestones. 
  These 
  pebbles 
  are 
  flat, 
  but 
  well 
  rounded 
  

   'On 
  the 
  margins, 
  showing 
  evidence 
  of 
  protracted 
  wear. 
  They. 
  

   :are 
  firmly 
  embedded 
  in 
  a 
  matrix 
  of 
  indurated 
  quartz 
  sand, 
  

   which 
  surrounds 
  them 
  and 
  fills 
  in 
  all 
  the 
  interstices. 
  This 
  

   bed 
  thins 
  out 
  toward 
  the 
  sides 
  of 
  the 
  channel. 
  On 
  the 
  con- 
  

   glomerate 
  lie 
  about 
  6 
  inches 
  of 
  shale 
  and 
  shaly 
  limestone, 
  and 
  

   these 
  are 
  succeeded 
  by 
  the 
  Onondaga 
  limestone. 
  The 
  width 
  of 
  the 
  

   channel, 
  which 
  is 
  clearly 
  an 
  erosion 
  channel, 
  is 
  about 
  i8 
  feet, 
  and 
  

   its 
  depth 
  is 
  about 
  3J 
  feet. 
  (Fig. 
  23) 
  

  

  From 
  the 
  point 
  where 
  this 
  channel 
  is 
  seen, 
  the 
  contact 
  can 
  be 
  

   traced 
  continuously 
  for 
  a 
  thousand 
  feet 
  or 
  more 
  eastward, 
  along 
  the 
  

   quarry 
  wall. 
  It 
  frequently 
  shows 
  a 
  thin 
  shaly 
  bed, 
  often 
  containing 
  

   quartz 
  grains, 
  lying 
  between 
  the 
  two 
  limestones. 
  

  

  ■Not 
  very 
  far 
  from 
  the 
  channel 
  just 
  described, 
  a 
  remarkable 
  "sand- 
  

   stone 
  *dike 
  " 
  penetrates 
  the 
  Siluric 
  limestones 
  of 
  the 
  quarry 
  wall. 
  

  

  