﻿48 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  reader 
  a 
  good 
  conception 
  of 
  the 
  character 
  of 
  the 
  folding. 
  It 
  is 
  

   quite 
  the 
  rule 
  throughout 
  this 
  region 
  of 
  Taconic 
  disturbance 
  to 
  find 
  

   the 
  strata 
  either 
  on 
  edge 
  or 
  making 
  high 
  angles 
  with 
  the 
  plane 
  of 
  

   the 
  horizon. 
  Many 
  times 
  the 
  folds 
  were 
  actually 
  overturned, 
  and 
  

   at 
  times 
  notable 
  thrust 
  faults 
  or 
  fractures 
  1 
  were 
  developed, 
  that 
  is, 
  

   the 
  strata 
  sometimes 
  broke 
  across 
  and 
  one 
  great 
  mass 
  was 
  pushed 
  

   over 
  another, 
  as 
  is 
  well 
  shown 
  in 
  many 
  places 
  in 
  southeastern 
  New 
  

   York. 
  These 
  facts 
  all 
  go 
  to 
  indicate 
  that 
  the 
  mountain-making 
  

   compressive 
  force 
  applied 
  to 
  the 
  region 
  was 
  of 
  the 
  extreme 
  type, 
  

   and 
  though 
  we 
  have 
  no 
  way 
  of 
  telling 
  just 
  how 
  high 
  the 
  range 
  may 
  

   have 
  been, 
  nevertheless 
  the 
  structural 
  features 
  and 
  the 
  vast 
  amount 
  

   of 
  erosion 
  since 
  the 
  folds 
  were 
  produced 
  clearly 
  indicate 
  that 
  the 
  

   uplift 
  was 
  at 
  least 
  several 
  thousand 
  feet. 
  The 
  Green 
  mountains, 
  

   White 
  mountains, 
  Berkshire 
  hills, 
  Highlands-of-the-Hudson, 
  and 
  

   the 
  Piedmont 
  plateau 
  are 
  in 
  a 
  sense 
  remnants 
  of 
  the 
  great 
  Taconic 
  

   range. 
  

  

  In 
  passing 
  westward 
  from 
  the 
  main 
  axis 
  of 
  the 
  Taconic 
  range, 
  

   the 
  folding 
  becomes 
  less 
  and 
  less 
  intense 
  and 
  finally 
  dies 
  out 
  alto- 
  

   gether. 
  This 
  fact 
  is 
  well 
  illustrated 
  by 
  figures 
  6, 
  8 
  and 
  9. 
  Along 
  

   the 
  Hudson 
  river 
  near 
  Albany, 
  the 
  strata 
  are 
  fairly 
  well 
  folded, 
  

   while 
  a 
  few 
  miles 
  westward 
  the 
  folds 
  disappear. 
  Passing 
  eastward 
  

   from 
  Albany 
  into 
  Rensselaer 
  county, 
  one 
  enters 
  a 
  region 
  of 
  exces- 
  

   sive 
  folding. 
  In 
  passing 
  westward 
  from 
  Poughkeepsie, 
  the 
  in- 
  

   tensity 
  of 
  the 
  folding 
  diminishes 
  somewhat, 
  but 
  the 
  shale 
  forma- 
  

   tion 
  is 
  distinctly 
  folded 
  where 
  it 
  passes 
  under 
  the 
  main 
  mass 
  of 
  the 
  

   Catskill 
  mountains. 
  Figure 
  6 
  clearly 
  illustrates 
  this 
  fact. 
  

  

  How 
  do 
  we 
  know 
  that 
  the 
  Taconic 
  disturbance 
  occurred 
  toward 
  

   the 
  close 
  of 
  'the 
  Ordovicic 
  period? 
  Another 
  inspection 
  of 
  figure 
  6 
  

   will 
  show 
  that 
  the 
  strata 
  of 
  the 
  next 
  succeeding 
  period 
  (Siluric) 
  

   rest 
  directly 
  upon 
  the 
  eroded 
  edges 
  of 
  the 
  folds 
  of 
  late 
  Ordovicic 
  

   rocks 
  (see 
  plate 
  25). 
  Hence 
  it 
  is 
  obvious 
  that 
  the 
  disturbance 
  oc- 
  

   curred 
  before 
  the 
  Siluric 
  strata 
  were 
  deposited. 
  What 
  was 
  the 
  

   condition 
  of 
  the 
  rest 
  of 
  the 
  State 
  just 
  after 
  the 
  Taconic 
  disturbance? 
  

   In 
  central 
  New 
  York, 
  near 
  Utica, 
  a 
  distinct 
  eroded 
  surface 
  at 
  the 
  

   summit 
  of 
  the 
  Ordovician 
  shales 
  proves 
  that 
  region 
  to 
  have 
  been 
  

   dry 
  land 
  toward 
  the 
  end 
  of 
  the 
  period. 
  On 
  the 
  north 
  side 
  of 
  the 
  

   Adirondacks 
  and 
  in 
  the 
  Champlain 
  valley 
  no 
  formation 
  younger 
  

   than 
  Ordovicic 
  shale 
  occurs, 
  and 
  all 
  evidence 
  points 
  to 
  uplift 
  of 
  

   that 
  area 
  into 
  dry 
  'land 
  toward 
  the 
  close 
  of 
  the 
  period. 
  Data 
  are 
  

   not 
  obtainable 
  for 
  western 
  New 
  York. 
  To 
  summarize: 
  Practically 
  

   all 
  of 
  northern-central, 
  eastern, 
  and 
  southeastern 
  New 
  York 
  {in- 
  

  

  1 
  See 
  figures 
  23 
  and 
  24 
  for 
  explanation 
  of 
  faults. 
  

  

  