﻿48 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  River 
  age. 
  Ruedemann 
  has 
  termed 
  this 
  limestone 
  the 
  Glens 
  Falls 
  

   limestone, 
  since 
  its 
  fauna 
  has 
  shown 
  it 
  to 
  lie 
  below 
  beds 
  of 
  the 
  

   Trenton 
  Falls 
  section. 
  1 
  

  

  THE 
  CANAJOHARIE 
  SHALE 
  

   BY 
  R. 
  RUEDEMANN 
  

  

  The 
  Canajoharie 
  shale 
  is 
  the 
  surface 
  rock 
  in 
  the 
  southernmost 
  

   area 
  of 
  the 
  Saratoga 
  quadrangle 
  and 
  thence 
  extends 
  northeast, 
  

   occupying 
  the 
  area 
  between 
  the 
  Snake 
  Hill 
  formation 
  of 
  the 
  eastern 
  

   trough 
  and 
  the 
  McGregor 
  fault 
  and 
  its 
  branches. 
  West 
  of 
  Sara- 
  

   toga 
  it 
  rests 
  directly 
  on 
  the 
  basal 
  or 
  Glens 
  Falls 
  limestone 
  and 
  south- 
  

   ward 
  the 
  formation 
  strikes 
  toward 
  the 
  Mohawk 
  river 
  near 
  which 
  

   it 
  passes 
  under 
  the 
  Schenectady 
  beds. 
  Northward 
  from 
  the 
  Schuy- 
  

   lerville 
  quadrangle 
  it 
  has 
  not 
  been 
  traced 
  beyond 
  Glens 
  Falls, 
  the 
  

   constituent 
  divisions 
  of 
  the 
  shale 
  belt 
  north 
  of 
  the 
  Hudson 
  valley 
  

   having 
  not 
  yet 
  been 
  differentiated. 
  

  

  This 
  formation, 
  which 
  is 
  most 
  typically 
  developed 
  in 
  the 
  Mohawk 
  

   valley, 
  has 
  been 
  fully 
  described 
  by 
  the 
  writer 
  in 
  Bulletin 
  162. 
  It 
  

   consists 
  almost 
  entirely 
  of 
  soft 
  black, 
  carbonaceous, 
  more 
  or 
  less 
  

   calcareous, 
  argillaceous 
  shales 
  and 
  is 
  therefore 
  quite 
  distinct 
  in 
  its 
  

   lithologic 
  characters 
  from 
  the 
  Normanskill-Snake 
  Hill 
  group, 
  al- 
  

   though 
  where 
  it 
  has 
  become 
  involved 
  in 
  the 
  folding, 
  as 
  in 
  

   Albany 
  county, 
  it 
  may 
  through 
  cleavage 
  and 
  slickensided 
  

   slip 
  planes 
  become 
  quite 
  similar 
  to 
  some 
  of 
  the 
  darker 
  shales 
  

   of 
  the 
  latter 
  formations. 
  It 
  lacks, 
  however, 
  the 
  smooth, 
  lighter 
  

   colored, 
  gray, 
  greenish 
  and 
  bluish 
  purely 
  argillaceous 
  shales 
  so 
  preva- 
  

   lent 
  in 
  them, 
  and 
  the 
  black 
  Canajoharie 
  shale 
  weathers 
  a 
  character- 
  

   istic 
  light 
  drab, 
  like 
  the 
  Utica 
  shale, 
  while 
  the 
  dark 
  shales 
  of 
  the 
  

   Normanskill-Snake 
  Hill 
  weather 
  grayish 
  brown 
  or 
  spotted 
  or 
  

   whitish 
  when 
  somewhat 
  siliceous. 
  Nor 
  does 
  the 
  Canajoharie 
  con- 
  

   tain 
  any 
  trace 
  of 
  the 
  white 
  weathering 
  chert 
  beds 
  and 
  grit 
  of 
  the 
  

   shales 
  of 
  the 
  eastern 
  trough. 
  A 
  sandstone 
  bed 
  2 
  to 
  3 
  feet 
  thick 
  was 
  

   observed 
  in 
  only 
  one 
  case 
  in 
  the 
  Snook 
  kill 
  below 
  Gansevoort, 
  

   although 
  thinner 
  layers 
  of 
  somewhat 
  sandy 
  shale 
  are 
  sometimes 
  met 
  

   with. 
  On 
  the 
  other 
  hand 
  there 
  frequently 
  occur 
  harder, 
  bluish 
  gray 
  

   mud 
  beds 
  indurated 
  by 
  calcite 
  which 
  are 
  mostly 
  3 
  to 
  6 
  inches 
  but 
  

   sometimes 
  3 
  to 
  4 
  feet 
  thick, 
  as 
  in 
  the 
  bank 
  of 
  the 
  Kayaderosseras 
  

   creek 
  above 
  Ballston 
  Spa. 
  These 
  mud 
  beds 
  break 
  conchoidal 
  or 
  

   lumpy 
  and 
  are 
  very 
  fine 
  grained. 
  The 
  shale 
  is 
  fissile 
  and 
  splintery 
  

  

  1 
  N. 
  Y. 
  State 
  Mus. 
  Bui. 
  162, 
  p. 
  22. 
  

  

  