﻿114 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  In 
  addition 
  to 
  the 
  evidence 
  which 
  the 
  general 
  stratigraphy 
  of 
  the 
  

   region 
  furnishes 
  as 
  to 
  the 
  early 
  date 
  of 
  some 
  of 
  this 
  warping, 
  evi- 
  

   dence 
  which 
  has 
  been 
  already 
  set 
  forth, 
  it 
  also 
  appears 
  that 
  the 
  

   Potsdam 
  and 
  Theresa 
  formations 
  are 
  somewhat 
  more 
  folded 
  than 
  

   are 
  the 
  overlying 
  limestones, 
  implying 
  that 
  they 
  were 
  somewhat 
  

   folded 
  prior 
  to 
  the 
  deposition 
  of 
  the 
  limestones. 
  This 
  is 
  best 
  

   shown 
  in 
  the 
  district 
  southwest 
  from 
  Clayton, 
  along 
  the 
  valley 
  of 
  

   French 
  creek, 
  where 
  the 
  Potsdam 
  is 
  arched 
  up 
  into 
  a 
  prominent 
  

   dome, 
  even 
  to 
  the 
  extent 
  of 
  bringing 
  up 
  the 
  Precambric. 
  The 
  

   dome 
  falls 
  away 
  to 
  the 
  sooith 
  with 
  rather 
  steep 
  dip, 
  there 
  is 
  scant 
  

   room 
  for 
  the 
  Theresa 
  formation 
  betsveen 
  the 
  south 
  margin 
  of 
  Pots- 
  

   dam 
  outcrop 
  and 
  the 
  Pamelia 
  front 
  just 
  beyond, 
  and 
  this 
  Pamelia 
  

   inface 
  passes 
  across 
  the 
  line 
  of 
  prolongation 
  of 
  this 
  fold 
  to 
  the 
  

   south 
  yet 
  shows 
  no 
  sign 
  of 
  being 
  affected 
  by 
  it, 
  being 
  precisely 
  

   the 
  same 
  cliff 
  of 
  horizontal 
  limestone 
  that 
  it 
  is 
  to 
  the 
  east 
  and 
  

   west 
  of 
  this 
  line. 
  It 
  is 
  of 
  course 
  possible 
  that 
  a 
  fault 
  lies 
  between^ 
  

   but 
  the 
  faults 
  of 
  the 
  district 
  are 
  infrequent 
  and 
  insignificant, 
  so 
  far 
  

   as 
  known, 
  so 
  that 
  the 
  supposition 
  seems 
  unlikely, 
  and 
  the 
  evidence 
  

   seems 
  to 
  clearly 
  pomt 
  to 
  folding 
  and 
  subsequent 
  wear, 
  during 
  the 
  

   long 
  time 
  interval 
  bet^veen 
  the 
  close 
  of 
  Theresa 
  and 
  the 
  beginning 
  of 
  

   Pamelia 
  deposition. 
  Evidence 
  of 
  less 
  distinctive 
  character 
  but 
  of 
  

   the 
  same 
  kind 
  is 
  also 
  forthcoming 
  elsewhere. 
  

  

  Two 
  series 
  of 
  low 
  folds 
  intersecting 
  at 
  right 
  angles 
  result 
  in 
  pro- 
  

   ducing 
  maxima 
  of 
  elevation 
  at 
  the 
  intersections 
  of 
  arches 
  and 
  of 
  

   depression 
  at 
  trough 
  intersections, 
  with 
  intermediate 
  conditions 
  

   where 
  trough 
  of 
  one 
  set 
  meets 
  arch 
  of 
  the 
  other. 
  In 
  other 
  words 
  

   the 
  axes 
  of 
  the 
  north-south 
  folds 
  are 
  themselves 
  folded 
  by 
  the 
  east- 
  

   west 
  folds, 
  producing 
  elevated 
  domes 
  along 
  the 
  arches, 
  and 
  depressed 
  

   basins 
  along 
  the 
  troughs. 
  A 
  prominent 
  feature 
  of 
  the 
  areal 
  maps 
  is 
  

   the 
  considerable 
  number 
  of 
  outliers 
  and 
  inliers 
  of 
  the 
  various 
  forma- 
  

   tions 
  there 
  shown. 
  ^ 
  The 
  abundant 
  Potsdam 
  outliers 
  on 
  the 
  Pre- 
  

   cambric 
  are 
  more 
  largely 
  due 
  to 
  the 
  irregularity 
  of 
  the 
  floor 
  on 
  which 
  

   the 
  formation 
  was 
  laid 
  down, 
  than 
  to 
  the 
  subsequent 
  folding. 
  But 
  

  

  1 
  Along 
  the 
  southern 
  margin 
  of 
  the 
  Theresa 
  sheet 
  are 
  shown 
  a 
  number 
  

   of 
  patches 
  of 
  Leray 
  limestone, 
  lying 
  to 
  the 
  north 
  of 
  the 
  main 
  line 
  of 
  

   outcrop 
  of 
  the 
  formation, 
  and 
  entirely 
  surrounded 
  by 
  the 
  older 
  Lowville 
  

   limestone. 
  The 
  Leray 
  limestone 
  formerly 
  extended 
  over 
  the 
  entire 
  dis- 
  

   trict, 
  and 
  has 
  been 
  worn 
  away 
  from 
  much 
  of 
  it, 
  these 
  representing, 
  out- 
  

   lying 
  patches 
  or 
  residuals 
  left 
  behind 
  in 
  this 
  general 
  process 
  of 
  removal, 
  

   hence 
  known 
  as 
  outliers. 
  Inliers 
  on 
  the 
  other 
  hand 
  are 
  patches 
  of 
  an 
  older 
  

   rock 
  entirely 
  surrounded 
  by 
  a 
  younger, 
  such 
  as 
  the 
  Precambric 
  by 
  French 
  

   creek 
  south 
  of 
  Clayton, 
  or 
  the 
  Low'ville 
  near 
  Threemile 
  Bay 
  and 
  Three- 
  

   niile 
  Bay 
  creek, 
  on 
  the 
  Clayton 
  sheet. 
  These 
  are 
  much 
  less 
  corilmon 
  than 
  

   outliers 
  and 
  are 
  strongly 
  indicative 
  of 
  a 
  warped 
  upper 
  surface 
  of 
  the 
  

   formation 
  constituting 
  the 
  inlier. 
  

  

  