﻿Report 
  of 
  the 
  State 
  Geologist. 
  679 
  

  

  extreme 
  end 
  of 
  Point 
  au 
  Koche 
  the 
  dip 
  is 
  north 
  thirty 
  degrees 
  

   west; 
  eighty 
  rods 
  to 
  the 
  west, 
  on 
  the 
  shore 
  of 
  ALontey's 
  bay 
  north 
  

   five 
  degrees 
  east; 
  south 
  of 
  Point 
  au 
  Roche 
  it 
  rapidly 
  swings 
  to 
  

   the 
  north. 
  The 
  geological 
  structure 
  on 
  l>le 
  la 
  Motte, 
  one 
  mile 
  

   east 
  of 
  Chazy 
  township, 
  whose 
  lengtli 
  from 
  north 
  to 
  south 
  nearly 
  

   equals 
  the 
  township's 
  length, 
  seems 
  to 
  indicate 
  a 
  Calciferous 
  

   age 
  for 
  these 
  Beekmantown 
  beds. 
  On 
  Isle 
  la 
  Motte 
  the 
  upper 
  

   Calciferous 
  is 
  exposed 
  at 
  the 
  southern 
  end 
  of 
  the 
  island, 
  fol- 
  

   lowed, 
  going 
  north, 
  by 
  the 
  entire 
  Chazy, 
  and 
  this 
  in 
  turn 
  by 
  

   the 
  Black 
  River 
  and 
  a 
  portion 
  of 
  the 
  Trenton, 
  the 
  whole 
  dip- 
  

   ping 
  to 
  the 
  north. 
  Apparently 
  coinciding 
  with 
  this 
  distribution 
  

   we 
  have 
  the 
  Chaz}^ 
  limestone 
  in 
  Chazy 
  township 
  sweeping 
  

   round 
  to 
  the 
  lake 
  shore 
  and 
  cutting 
  out 
  the 
  Trenton. 
  If 
  the 
  

   coincidence 
  is 
  real, 
  and 
  not 
  merely 
  apparent, 
  we 
  should 
  expect 
  

   to 
  find 
  the 
  Calciferous 
  following 
  the 
  Chazy 
  to 
  the 
  south 
  in 
  a 
  

   similar 
  sweep, 
  in 
  other 
  words, 
  occupying 
  the 
  stratigraphic 
  

   position 
  in 
  which 
  the 
  debatable 
  beds 
  are 
  found 
  in 
  southern 
  

   Chazy 
  and 
  North 
  Beekmantown. 
  These 
  beds 
  are 
  also 
  in 
  large 
  

   part 
  like 
  the 
  Calciferous 
  lithologically, 
  but 
  this 
  is 
  not 
  true 
  of 
  

   that 
  portion 
  of 
  them 
  under 
  discussion, 
  which 
  more 
  nearly 
  

   resemble 
  the 
  Trenton. 
  In 
  the 
  top 
  layer 
  of 
  these 
  beds 
  on 
  Point 
  

   au 
  Roche, 
  the 
  layer 
  being 
  markedly 
  pyritiferous, 
  a 
  small 
  gas- 
  

   tropod 
  and 
  a 
  Zeperdita-like 
  form 
  are 
  very 
  abundant, 
  and 
  may 
  

   prove 
  sufficient 
  to 
  p< 
  -sitively 
  determine 
  the 
  age.* 
  Rocks 
  similar 
  

   to 
  those 
  in 
  South 
  Beekmantown 
  and 
  carrying 
  the 
  same 
  Trenton 
  

   fossils 
  (Asaphus 
  gigas 
  is 
  the 
  most 
  common 
  form) 
  are 
  exposed 
  all 
  

   over 
  Cumberland 
  Head 
  in 
  Plattsburgh 
  township, 
  their 
  peculiar 
  

   secondary 
  cleavage 
  having 
  already 
  been 
  described. 
  Similar 
  

   beds, 
  with 
  the 
  same 
  peculiarities, 
  appear 
  on 
  the 
  lake 
  shore 
  just 
  

   south 
  of 
  the 
  chYy 
  of 
  Plattsburgh, 
  forming 
  a 
  considerable 
  cliff. 
  On 
  

   the 
  shore 
  at 
  Bluff 
  Point 
  the 
  Trenton 
  is 
  again 
  exposed 
  in 
  a 
  cliff 
  

   some 
  fifty 
  feet 
  in 
  height. 
  Here 
  it 
  is 
  lighter 
  colored 
  and 
  more 
  

   massive 
  than 
  the 
  black 
  slaty 
  beds, 
  carries 
  a 
  more 
  abundant 
  

   fauna, 
  and 
  seems 
  to 
  represent 
  a 
  somewhat 
  higher 
  horizon. 
  A 
  

   large 
  Strojphomena 
  is 
  the 
  most 
  abundant 
  and 
  conspicuous 
  form, 
  

   numerous 
  individuals 
  showing 
  on 
  the 
  face 
  of 
  the 
  cliff. 
  On 
  

   ascending 
  the 
  cliff 
  and 
  thence 
  following 
  up 
  the 
  slope 
  to 
  the 
  

  

  *For 
  the 
  geology 
  of 
  Isle 
  la 
  Motte 
  see 
  Brainerd 
  and 
  SeelyioBull. 
  Geol. 
  Soc. 
  Am., 
  vol. 
  II, 
  

   p. 
  297. 
  

  

  