﻿GEOLOGY 
  OF 
  THOUSAND 
  ISLANDS 
  REGION 
  83 
  

  

  Unfortunately 
  no 
  good 
  sections 
  were 
  found 
  in 
  the 
  northwestern 
  

   portion 
  of 
  the 
  area, 
  permitting 
  a 
  comparison 
  with 
  that 
  of 
  Lowville 
  

   as 
  to 
  thickness 
  and 
  arrangement 
  of 
  horizons. 
  

  

  Section 
  at 
  railroad 
  bridge 
  at 
  Lowville 
  (type 
  section) 
  

   Lowville 
  section 
  

  

  6' 
  Cherty 
  beds. 
  Dark 
  blue, 
  finely 
  granular 
  limestone, 
  dirty 
  white 
  

  

  weathering. 
  Columnaria 
  horizon 
  at 
  base 
  

  

  i' 
  6'' 
  Bed 
  full 
  of 
  horizontal 
  worm 
  tubes. 
  Chert 
  horizon 
  at 
  base 
  

  

  5' 
  9" 
  Transitional 
  bed 
  from 
  Leray 
  to 
  typical 
  Lowville. 
  In 
  aspect 
  like 
  

   cherty 
  beds 
  with 
  a 
  few 
  cherts, 
  but 
  contains 
  also 
  Tetradium 
  

   c 
  e 
  1 
  1 
  u 
  1 
  o 
  s 
  u 
  m 
  , 
  besides 
  Leperditia 
  fabulites, 
  

   Rafinesquina 
  minnesotensis, 
  and 
  other 
  brachiopods 
  

   and 
  bryozoans 
  

   Base 
  of 
  Leray 
  

  

  3' 
  Dove 
  limestone, 
  massive. 
  Phytopsis 
  tubulosum 
  com- 
  

  

  mon 
  near 
  top 
  ; 
  a 
  few 
  Tetradium 
  cells 
  

  

  3' 
  i'^ 
  Compact 
  dark 
  dove 
  limestone, 
  full 
  of 
  fossils 
  (Tetradium, 
  gastro- 
  

   pods, 
  lamellibranchs) 
  and 
  of 
  crystalline 
  calcite 
  

  

  4' 
  9" 
  Thin 
  bedded, 
  dove 
  limestone, 
  full 
  of 
  Tetradiums 
  (form 
  with 
  nar- 
  

   row, 
  round 
  tubes) 
  

   5" 
  Dark, 
  fine 
  grained 
  impure 
  limestone 
  with 
  argillaceous 
  streaks, 
  

   containing 
  a 
  small 
  Monticulipora 
  

  

  2' 
  4" 
  Lighter, 
  massive 
  bed 
  of 
  dove 
  limestone 
  with 
  few 
  Tetradiums. 
  

   Lowest 
  8 
  inches 
  black, 
  with 
  thin 
  seams 
  of 
  flint 
  

  

  4"- 
  Y' 
  Stratum 
  of 
  granular, 
  light 
  gray 
  limestone 
  full 
  of 
  lamellibranchs 
  

   and 
  gastropods, 
  their 
  shells 
  filled 
  with 
  calcite 
  

  

  i' 
  3'' 
  Black, 
  massive, 
  crystalline 
  limestone, 
  full 
  of 
  Tetradium 
  

  

  3' 
  4" 
  Black 
  to 
  dark 
  gray 
  thin 
  bedded 
  dove 
  limestone, 
  containing 
  a 
  few 
  

   Phytopsis 
  

   4'' 
  Same 
  rock 
  as 
  above, 
  but 
  full 
  of 
  a 
  narrow 
  form 
  of 
  Phytopsis 
  

   4'' 
  Black, 
  dove 
  limestone 
  stratum 
  full 
  of 
  crystalline 
  calcite 
  

  

  i' 
  7" 
  Dark 
  gray, 
  granular 
  limestone 
  with 
  many 
  calcite 
  crystals. 
  Bottom 
  

   of 
  quarry 
  

  

  4' 
  Dark 
  gray, 
  thin 
  bedded, 
  dove 
  limestone, 
  weathering 
  shaly 
  

  

  4' 
  Harder, 
  argillaceous 
  limestone 
  

  

  3' 
  to" 
  Shaly 
  dove 
  limestone, 
  varies 
  much, 
  very 
  shaly 
  in 
  middle, 
  full 
  of 
  

   sand 
  grains, 
  contains 
  a 
  few 
  lamellibranchs 
  

  

  1' 
  Hard, 
  oolitic 
  blue 
  limestone, 
  full 
  of 
  quartz 
  grains 
  and 
  pebbles 
  

  

  (i"-\Q)" 
  Shaly 
  bed 
  with 
  seams 
  of 
  quartz 
  grains 
  or 
  grit 
  bands 
  

  

  o- 
  3'+ 
  Dark 
  bluish 
  gray 
  limestone, 
  full 
  of 
  pebbles, 
  shale 
  below. 
  Very 
  

   variable 
  in 
  thickness. 
  Unconformity. 
  Base 
  of 
  Lowville 
  

  

  i' 
  10" 
  Gray 
  and 
  pinkish 
  granular 
  limestone, 
  dove 
  in 
  parts 
  

   4" 
  Thin 
  bedded, 
  shaly 
  limestone, 
  sand 
  grains 
  near 
  top 
  

  

  i' 
  10" 
  Dove, 
  dark 
  mottled, 
  fine 
  grained 
  limestone, 
  typical 
  upper 
  Pamelia 
  

  

  i' 
  7'' 
  Dove 
  limestone 
  v/ith 
  argillaceous 
  reticulation, 
  light 
  pink 
  in 
  parts, 
  

   weathering 
  shaly 
  

   9" 
  Bluish 
  black 
  flinty 
  dove 
  limestone 
  

  

  10" 
  Gray, 
  granular 
  limestone 
  with 
  calcite 
  and 
  quartz 
  grains, 
  in 
  parts 
  

   conglomeratic, 
  a 
  few 
  fossils. 
  (Rafinesquina 
  incras- 
  

   s 
  a 
  t 
  a 
  ) 
  

  

  1' 
  5" 
  Light 
  dove 
  limestone, 
  somewhat 
  argillaceous, 
  coarsely 
  laminated. 
  

   Phytopsis 
  on 
  top 
  

  

  2' 
  Grayish, 
  bluish, 
  blocky, 
  subgranular 
  limestone 
  

  

  i' 
  Compact 
  bed 
  of 
  harder, 
  light 
  bluish 
  gray 
  limestone 
  

  

  l'+ 
  Dove, 
  light 
  gray 
  limestone 
  with 
  crystalline 
  specks 
  

  

  