﻿Report 
  of 
  the 
  State 
  Geologist. 
  619 
  

  

  bedded, 
  coarse-grained, 
  light-colored 
  crinoidal 
  limestone. 
  This 
  is 
  

   underlaid 
  by 
  a 
  series 
  of 
  thin-bedded, 
  dark 
  limestones, 
  with 
  

   more 
  or 
  less 
  intercalated 
  black 
  shale, 
  which 
  is 
  of 
  general 
  occur- 
  

   rence 
  and 
  constitutes 
  an 
  upper 
  member 
  eastward, 
  or 
  the 
  entire 
  

   formation. 
  Then 
  there 
  is 
  a 
  very 
  massive, 
  dark, 
  coarse 
  lime- 
  

   stone 
  which 
  begins 
  as 
  a 
  basal 
  series 
  near 
  the 
  Mohawk 
  in 
  the 
  

   eastern 
  part 
  of 
  Montgomery 
  county 
  and 
  extends 
  to 
  the 
  south- 
  

   eastward, 
  coming 
  out 
  in 
  great 
  force 
  at 
  Glens 
  Falls, 
  where 
  it 
  is 
  

   extensively 
  quarried 
  for 
  black 
  marble. 
  The 
  upper 
  massive 
  

   series 
  appears 
  to 
  be 
  a 
  development 
  of 
  the 
  upper 
  portion 
  of 
  the 
  

   thin-bedded 
  Trenton, 
  a 
  feature 
  which 
  is 
  exhibited 
  in 
  the 
  fine 
  

   series 
  of 
  exposures 
  extending 
  along 
  the 
  south 
  slope 
  of 
  the 
  "West 
  

   Canada 
  creek 
  valley 
  from 
  Newport 
  to 
  Trenton 
  Falls. 
  The 
  lower 
  

   massive 
  series 
  appears 
  to 
  be 
  an 
  older 
  member 
  of 
  the 
  formation 
  

   overlapped 
  westward 
  and 
  apparently 
  to 
  some 
  extent 
  near 
  its 
  

   southern 
  termination 
  by 
  the 
  thin-bedded 
  series. 
  The 
  greatest 
  

   development 
  of 
  the 
  Trenton 
  which 
  I 
  have 
  observed 
  is 
  at 
  Trenton 
  

   Falls, 
  where 
  there 
  appears 
  to 
  be 
  a 
  thickness 
  of 
  1 
  20 
  feet, 
  although 
  

   I 
  made 
  no 
  careful 
  measurement. 
  Owing 
  to 
  the 
  dip 
  of 
  the 
  beds 
  

   down 
  stream 
  and 
  the 
  variability 
  of 
  the 
  rate 
  of 
  dip 
  the 
  total 
  

   amount 
  of 
  fall 
  is 
  not 
  a 
  measure 
  of 
  the 
  thickness. 
  

  

  In 
  the 
  accompanying 
  plates 
  some 
  idea 
  is 
  given 
  of 
  the 
  aspect 
  

   of 
  the 
  several 
  members 
  of 
  the 
  formation 
  at 
  Trenton 
  Falls 
  and 
  of 
  

   a 
  portion 
  of 
  the 
  falls 
  and 
  gorge 
  to 
  which 
  they 
  give 
  rise. 
  » 
  

  

  Descending 
  the 
  West 
  Canada 
  creek 
  valley 
  the 
  Trenton 
  lime- 
  

   stones 
  gradually 
  decrease 
  in 
  thickness, 
  and 
  south 
  of 
  Middleville 
  

   I 
  found 
  only 
  thirty 
  feet, 
  consisting 
  entirely 
  of 
  thin-bedded 
  mem- 
  

   bers. 
  Descending 
  the 
  Mohawk 
  the 
  thinning 
  gradually 
  continues 
  

   to 
  Canajoharie, 
  where 
  the 
  amount 
  is 
  only 
  six 
  feet. 
  The 
  forma- 
  

   tion 
  is 
  well 
  exposed 
  on 
  the 
  creek 
  behind 
  Canajoharie. 
  It 
  con- 
  

   sists 
  of 
  thin-bedded, 
  dark-colored, 
  semi-crystalline 
  limestones, 
  

   with 
  black 
  shaly 
  intercalations 
  lying 
  on 
  a 
  very 
  uneven 
  concre- 
  

   tionary 
  surface 
  of 
  the 
  Calciferous 
  sandrock 
  to 
  which 
  its 
  beds 
  are 
  

   flexed 
  to 
  conform. 
  They 
  are, 
  however, 
  sharply 
  separated 
  at 
  the 
  

   contact 
  by 
  an 
  apparent 
  unconformity. 
  In 
  plate 
  5 
  some 
  of 
  these 
  

   features 
  are 
  shown 
  together 
  with 
  the 
  overlying 
  Utica 
  beds. 
  

  

  The 
  thickness 
  gradually 
  increases 
  eastward 
  and 
  northward 
  

   from 
  this 
  locality. 
  At 
  Tribes 
  Hill 
  station 
  the 
  lower 
  massive 
  mem- 
  

   ber 
  makes 
  its 
  appearance 
  and 
  is 
  extensively 
  quarried. 
  There 
  

  

  