﻿GEOLOGY 
  OF 
  THE 
  NORTH 
  CREEK 
  QUADRANGLE 
  45 
  

  

  The 
  important 
  outlier 
  at 
  Wells 
  (Lake 
  Pleasant 
  sheet), 
  which 
  

   shows 
  rocks 
  from 
  Potsdam 
  to 
  Canajoharie, 
  has 
  been 
  known 
  since 
  

   the 
  early 
  days 
  of 
  the 
  State 
  Survey. 
  The 
  nearby 
  occurrences 
  of 
  

   Little 
  Falls 
  dolomite 
  along 
  the 
  southern 
  portion 
  of 
  Lake 
  George 
  

   should 
  also 
  be 
  mentioned. 
  

  

  Within 
  the 
  map 
  limits, 
  certain 
  drift 
  boulders 
  are 
  significant 
  as 
  

   showing 
  proximity 
  to 
  concealed 
  outcrops 
  or 
  ledges 
  which 
  were 
  

   scraped 
  off 
  by 
  ice 
  erosion. 
  Thus 
  a 
  fragment 
  of 
  Potsdam 
  sandstone 
  

   2 
  feet 
  across 
  and 
  very 
  angular 
  was 
  seen 
  just 
  east 
  of 
  the 
  old 
  garnet 
  

   mine 
  near 
  Daggett 
  pond, 
  and 
  many 
  Potsdam 
  fragments 
  up 
  to 
  I 
  foot 
  

   across 
  occur 
  in 
  the 
  river 
  valley 
  bottom 
  between 
  Moon 
  and 
  Heath 
  

   mountains. 
  

  

  The 
  occurrences 
  of 
  early 
  Paleozoic 
  marine 
  strata 
  on 
  all 
  sides 
  of 
  

   the 
  North 
  Creek 
  quadrangle 
  furnish 
  practically 
  conclusive 
  evidence 
  

   that 
  much, 
  if 
  not 
  all, 
  of 
  the 
  area 
  of 
  the 
  quadrangle 
  was 
  covered 
  

   by 
  that 
  early 
  Paleozoic 
  sea. 
  Thus 
  the 
  Potsdam 
  (upper 
  Cambric) 
  

   sea, 
  which 
  encroached 
  over 
  northern 
  New 
  York 
  from 
  the 
  north- 
  

   east, 
  must 
  have 
  swept 
  over 
  the 
  North 
  Creek 
  region 
  and 
  this 
  was 
  

   quite 
  certainly 
  succeeded 
  by 
  the 
  Theresa 
  and 
  Little 
  Falls 
  seas. 
  

   Regarding 
  the 
  presence 
  or 
  absence 
  of 
  the 
  Ordovician 
  sea, 
  we 
  have 
  

   no 
  positive 
  knowledge, 
  though 
  the 
  Wells 
  outlier 
  suggests 
  that 
  it, 
  

   too, 
  was 
  present. 
  

  

  It 
  is 
  well 
  known 
  that 
  when 
  the 
  Potsdam 
  sea 
  encroached 
  upon 
  the 
  

   eastern 
  Adirondacks, 
  the 
  region 
  was 
  greatly 
  worn 
  down 
  to 
  the 
  con- 
  

   dition 
  of 
  nearly 
  a 
  peneplain. 
  Since 
  some 
  portions 
  stood 
  out 
  above 
  

   the 
  general 
  level 
  of 
  the 
  peneplain, 
  it 
  is 
  quite 
  possible 
  that 
  the 
  Pots- 
  

   dam 
  sea, 
  and 
  even 
  the 
  later 
  Cambric, 
  did 
  not 
  cover 
  the 
  higher 
  por- 
  

   tions 
  as 
  Professor 
  Kemp 
  has 
  suggested. 
  At 
  any 
  rate 
  the 
  evidence 
  

   is 
  strong 
  that 
  very 
  much 
  if 
  not 
  all 
  of 
  the 
  North 
  Creek 
  area 
  was 
  

   covered 
  by 
  the 
  late 
  Cambric 
  sea 
  and 
  probably 
  also 
  by 
  the 
  Ordovician 
  

   sea. 
  The 
  deposits 
  made 
  in 
  those 
  seas 
  have 
  all 
  been 
  removed 
  by 
  

   erosion 
  except 
  for 
  the 
  small 
  outlying 
  masses 
  above 
  described. 
  It 
  is 
  

   important 
  to 
  note 
  that 
  each 
  one 
  of 
  these 
  outliers 
  has 
  been 
  very 
  con- 
  

   siderably 
  faulted 
  downward 
  from 
  the 
  original 
  position 
  of 
  the 
  strata 
  

   and 
  thus 
  they 
  have 
  been 
  protected 
  against 
  complete 
  removal 
  by 
  ero- 
  

   sion 
  during 
  so 
  many 
  million 
  years. 
  

  

  STRUCTURAL 
  FEATURES 
  

  

  FAULTS 
  

  

  General 
  considerations. 
  That 
  the 
  eastern 
  Adirondacks 
  are 
  ex- 
  

   tensively 
  faulted 
  has 
  been 
  recognized 
  for 
  some 
  years, 
  but 
  thus 
  far 
  

   comparatively 
  little 
  attention 
  has 
  been 
  paid 
  to 
  the 
  detailed 
  study 
  

  

  