﻿88 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  the 
  Pamelia 
  (Chazy) 
  limestone 
  was 
  being 
  deposited 
  in 
  the 
  Black 
  

   river 
  valley 
  and 
  also 
  locally 
  along 
  the 
  eastern 
  border 
  when 
  cer- 
  

   tain 
  other 
  limestones 
  of 
  the 
  Chazy 
  group 
  were 
  being 
  laid 
  down 
  

   in 
  the 
  Champlain 
  trough. 
  

  

  For 
  most 
  part 
  the 
  various 
  Black 
  River 
  limestone 
  members 
  are 
  

   thin 
  and 
  patchy 
  in 
  their 
  distribution 
  except 
  in 
  the 
  Black 
  river 
  

   valley, 
  and 
  no 
  attempt 
  is 
  here 
  made 
  to 
  enter 
  into 
  the 
  details 
  of 
  

   physiography 
  and 
  oscillations 
  of 
  level 
  in 
  Black 
  River 
  time. 
  Suf- 
  

   fice 
  it 
  to 
  say 
  that 
  early 
  Black 
  River 
  (Lowville) 
  limestone 
  is 
  pres- 
  

   ent 
  on 
  all 
  sides 
  of 
  the 
  southern 
  Adirondacks 
  and 
  in 
  the 
  outlier 
  

   at 
  Wells, 
  it 
  being 
  but 
  a 
  few 
  feet 
  thick 
  in 
  the 
  eastern 
  and 
  southern 
  

   portions 
  and 
  fifty 
  to 
  sixty 
  feet 
  thick 
  along 
  the 
  western 
  border. 
  

   Therefore, 
  judging 
  by 
  the 
  areal 
  distribution 
  and 
  thinness 
  of 
  the 
  

   Lowville 
  we 
  are 
  practically 
  certain 
  that 
  the 
  central 
  western 
  por- 
  

   tion 
  of 
  the 
  Adirondack 
  area 
  was 
  not 
  submerged 
  during 
  early 
  

   Black 
  River 
  time. 
  Thin 
  limestone 
  deposits 
  of 
  late 
  Black 
  River 
  

   age 
  are 
  confined 
  to 
  the 
  vicinity 
  of 
  Watertown 
  (Watertown 
  

   limestone) 
  and 
  along 
  the 
  eastern 
  and 
  southeastern 
  borders 
  of 
  the 
  

   Adirondacks 
  (Amsterdam 
  limestone) 
  with 
  deposition 
  in 
  these 
  

   two 
  regions 
  not 
  occurring 
  simultaneously. 
  Thus 
  there 
  could 
  not 
  

   have 
  been 
  anything 
  like 
  extensive 
  submergence 
  of 
  the 
  southern 
  

   Adirondacks 
  in 
  late 
  Black 
  River 
  time. 
  

  

  The 
  widespread 
  unconformity 
  at 
  the 
  summit 
  of 
  the 
  Black 
  River 
  

   group 
  of 
  limestones 
  shows 
  that 
  a 
  general 
  upward 
  oscillation 
  occurred 
  

   and 
  that 
  the 
  whole 
  southern 
  Adirondack 
  region 
  became 
  dry 
  land 
  

   before 
  the 
  succeeding 
  Trenton 
  submergence. 
  

  

  Late 
  Ordovicic. 
  During 
  Trenton 
  time 
  there 
  was 
  a 
  widespread 
  

   submergence 
  of 
  much 
  of 
  the 
  southern 
  Adirondack 
  region 
  as 
  shown 
  

   by 
  the 
  existence 
  of 
  Trenton 
  limestone 
  or 
  shale 
  hundreds 
  of 
  feet 
  

   thick 
  on 
  all 
  sides 
  of 
  the 
  region 
  and 
  even 
  in 
  the 
  outlier 
  at 
  Wells. 
  The 
  

   limestone 
  is 
  almost 
  wholly 
  confined 
  to 
  the 
  western 
  side, 
  there 
  being 
  

   but 
  a 
  few 
  feet 
  of 
  limestone 
  at 
  the 
  base 
  of 
  the 
  Trenton 
  on 
  the 
  

   eastern 
  side 
  where 
  thick 
  shales 
  (Canajoharie 
  and 
  Schenectady) 
  

   comprise 
  nearly 
  the 
  whole 
  section. 
  

  

  Considering 
  the 
  thickness 
  (about 
  four 
  hundred 
  feet) 
  of 
  the 
  

   Trenton 
  limestone 
  in 
  the 
  upper 
  Black 
  River 
  valley 
  and 
  the 
  slope 
  of 
  

   the 
  surface 
  9 
  on 
  which 
  deposition 
  occurred, 
  the 
  Trenton 
  sea 
  could 
  not 
  

   have 
  extended 
  more 
  than 
  forty 
  miles 
  eastward 
  into 
  the 
  Adirondack 
  

   area. 
  If 
  we 
  consider 
  deposition 
  to 
  have 
  taken 
  place 
  in 
  a 
  distinctly 
  

   downwarped 
  trough, 
  then 
  the 
  Trenton 
  sea 
  must 
  have 
  extended 
  in 
  

  

  9 
  Page 
  43- 
  

  

  