﻿THE 
  GEOLOGICAL 
  HISTORY 
  OF 
  NEW 
  YORK 
  STATE 
  3 
  1 
  

  

  DISTRIBUTION, 
  THICKNESS 
  AND 
  AGE 
  OF 
  THE 
  GRENVILLE 
  

  

  The 
  Grenville 
  is 
  associated 
  with 
  rocks 
  of 
  younger 
  age 
  in 
  the 
  

   Adirondack 
  region, 
  so 
  that 
  the 
  formation 
  is 
  not 
  present 
  as 
  a 
  single, 
  

   continuous 
  mass 
  of 
  surface 
  rock 
  covering 
  the 
  whole 
  area. 
  It 
  is, 
  

   however, 
  so 
  abundant 
  and 
  widespread 
  in 
  great 
  and 
  small 
  areas 
  

   throughout 
  the 
  Adirondack 
  province 
  that 
  we 
  may 
  confidently 
  assert 
  

   that 
  this 
  whole 
  district 
  was 
  under 
  water 
  during 
  Grenville 
  time. 
  As 
  

   the 
  geologic 
  structure 
  strongly 
  suggests 
  and 
  as 
  certain 
  deep 
  wells 
  

   prove, 
  rocks 
  of 
  this 
  age 
  must 
  extend, 
  under 
  cover 
  of 
  the 
  later 
  

   Paleozoic 
  sediments, 
  for 
  a 
  considerable 
  distance 
  beyond 
  the 
  Adiron- 
  

   dack 
  area. 
  Precambric 
  rocks 
  have 
  long 
  been 
  recognized 
  in 
  the 
  

   Highland's 
  district 
  of 
  the 
  lower 
  Hudson 
  and 
  recent 
  work 
  makes 
  it 
  

   practically 
  certain 
  that 
  strata 
  of 
  Grenville 
  age 
  exist 
  there. 
  Pre- 
  

   cambric 
  (doubtless 
  including 
  Grenville) 
  occurs 
  along 
  the 
  western 
  

   border 
  of 
  New 
  England 
  and 
  it 
  should 
  also 
  be 
  mentioned 
  that 
  Gren- 
  

   ville 
  strata 
  are 
  extensive 
  over 
  much 
  of 
  southeastern 
  Canada. 
  Pres- 
  

   ence 
  of 
  Grenville 
  strata 
  in 
  southwestern 
  New 
  York 
  is 
  somewhat 
  

   doubtful 
  because, 
  if 
  there, 
  they 
  are 
  effectually 
  concealed 
  under 
  the 
  

   heavy 
  cover 
  of 
  Paleozoic 
  strata. 
  The 
  positive 
  existence 
  of 
  Gren- 
  

   ville, 
  however, 
  just 
  to 
  the 
  north 
  in 
  Canada 
  and 
  in 
  northern 
  and 
  

   southeastern 
  New 
  York, 
  makes 
  it 
  more 
  than 
  likely 
  that 
  the 
  Gren- 
  

   ville 
  underlies 
  the 
  Paleozoic 
  rocks 
  of 
  western 
  New 
  York 
  also. 
  Such 
  

   a 
  widespread 
  distribution 
  of 
  the 
  Grenville 
  sediments 
  shows 
  that 
  

   deposition 
  went 
  on 
  in 
  a 
  very 
  large 
  body 
  of 
  water 
  ; 
  large 
  enough, 
  in 
  

   fact, 
  to 
  be 
  called 
  an 
  ocean. 
  Thus, 
  bearing 
  in 
  mind 
  all 
  the 
  facts, 
  we 
  

   are 
  led 
  to 
  the 
  important 
  conclusion 
  that, 
  during 
  Grenville 
  time, 
  all 
  

   of 
  northern 
  and 
  eastern 
  and 
  probably 
  southwestern 
  New 
  York 
  was 
  

   under 
  the 
  sea. 
  In 
  other 
  words, 
  the 
  most 
  ancient 
  known 
  geographic 
  

   condition 
  in 
  New 
  York 
  was 
  a 
  great 
  expanse 
  of 
  ocean 
  water 
  cover- 
  

   ing 
  most, 
  if 
  not 
  all, 
  of 
  the 
  State. 
  

  

  As 
  the 
  rocks 
  are 
  badly 
  disturbed 
  and 
  folded, 
  and 
  as 
  the 
  top 
  or 
  

   bottom 
  of 
  the 
  formation 
  has 
  never 
  been 
  recognized 
  as 
  such, 
  it 
  is 
  

   impossible 
  to 
  give 
  anything 
  like 
  an 
  exact 
  figure 
  for 
  the 
  thickness 
  of 
  

   the 
  Grenville 
  rocks. 
  Continuous 
  successions 
  of 
  strata 
  have 
  been 
  

   observed 
  in 
  enough 
  places, 
  however, 
  to 
  make 
  it 
  certain 
  that 
  Gren- 
  

   ville 
  strata 
  were 
  piled, 
  one 
  layer 
  upon 
  another, 
  to 
  a 
  thickness 
  of 
  

   many 
  thousands 
  of 
  feet. 
  This 
  clearly 
  implies 
  that 
  the 
  Grenville 
  

   ocean 
  existed 
  for 
  a 
  vast 
  length 
  of 
  time 
  which 
  must 
  ibe 
  measured 
  

   by 
  no 
  less 
  than 
  a 
  few 
  million 
  years, 
  because 
  in 
  the 
  light 
  of 
  all 
  our 
  

   knowledge 
  regarding 
  the 
  rate 
  of 
  deposition 
  of 
  sediments, 
  such 
  a 
  

   very 
  long 
  time 
  was 
  necessary 
  for 
  the 
  accumulation 
  of 
  so 
  thick 
  a 
  

   mass 
  of 
  rocks. 
  It 
  does 
  not 
  necessarily 
  follow 
  that 
  the 
  Grenville 
  

  

  