﻿136 
  NEW 
  YORK 
  STATE 
  MUSEUM 
  

  

  River 
  village, 
  Watertown, 
  Brownville 
  and 
  Dexter; 
  and 
  at 
  each 
  

   locality 
  use 
  is 
  made 
  of 
  the 
  water 
  power. 
  Every 
  one 
  of 
  the 
  falls 
  

   is 
  over 
  the 
  massive 
  Leray 
  limestone 
  into 
  the 
  Lowville 
  beneath, 
  as 
  

   well 
  shown 
  in 
  Ulrich's 
  excellent 
  panoramic 
  view 
  of 
  the 
  main 
  

   fall 
  at 
  Watertown 
  [pi. 
  42]. 
  There 
  are 
  minor 
  falls 
  of 
  the 
  same 
  

   type 
  between 
  the 
  chief 
  localities. 
  Below 
  the 
  fall 
  the 
  river 
  flows 
  

   along 
  in 
  the 
  Lowville 
  until 
  the 
  steepened 
  dip 
  on 
  the 
  western 
  limb 
  

   of 
  an 
  anticlinal 
  fold 
  carries 
  the 
  overlying 
  Leray 
  limestone 
  down 
  

   to, 
  and 
  beneath, 
  the 
  water 
  surface, 
  forming 
  the 
  bottom 
  of 
  a 
  shallow, 
  

   synclinal 
  trough 
  [see 
  pi. 
  28 
  for 
  such 
  steepened 
  dip 
  at 
  Brown- 
  

   ville]. 
  In 
  this 
  the 
  dip 
  flattens, 
  and 
  then 
  becomes 
  low 
  east, 
  bring- 
  

   ing 
  the 
  Leray 
  base 
  back 
  to 
  stream 
  level, 
  and 
  giving 
  opportunity 
  

   for 
  development 
  of 
  the 
  fall 
  as 
  the 
  water 
  passes 
  on 
  to 
  

   the 
  less 
  resistant 
  Lowville 
  beneath, 
  the 
  fall 
  so 
  begun 
  slowly 
  

   cutting 
  back 
  up 
  stream 
  with 
  gradual 
  increase 
  in 
  hight. 
  Down 
  

   stream 
  the 
  river 
  remains 
  on 
  the 
  Lowville 
  under 
  the 
  general 
  low 
  

   anticlinal 
  arch, 
  until 
  the 
  drop 
  of 
  its 
  western 
  limb 
  again 
  puts 
  the 
  

   Leray 
  limestone 
  beneath 
  the 
  river 
  level, 
  with 
  repetition 
  of 
  

   the 
  previous 
  conditions 
  and 
  another 
  fall 
  where 
  the 
  limestone 
  comes 
  

   back 
  again. 
  Because 
  of 
  the 
  westerly 
  dip 
  the 
  western 
  limb 
  of 
  the 
  

   anticlines 
  is 
  steeper 
  than 
  the 
  eastern, 
  and 
  the 
  river 
  cuts 
  the 
  bottom 
  

   of 
  each 
  syncline 
  at 
  substantially 
  the 
  same 
  horizon. 
  The 
  diagram 
  

   [fig. 
  12] 
  will 
  illustrate 
  the 
  conditions, 
  which 
  are 
  somewhat 
  excep- 
  

   tional, 
  better 
  than 
  can 
  be 
  done 
  verbally. 
  

  

  ' 
  Fig. 
  12 
  Diagram 
  illustrating 
  the 
  rock 
  structure 
  which 
  gives 
  rise 
  to 
  the 
  successive 
  falls 
  

   in 
  the 
  Black 
  river, 
  the 
  heavy 
  line 
  representing 
  the 
  river 
  bed 
  with 
  three 
  falls, 
  and 
  the 
  sinu- 
  

   ous 
  dotted 
  hne 
  the 
  base 
  of 
  the 
  Leray 
  limestone, 
  showing 
  how, 
  due 
  to 
  the 
  folding 
  

   each 
  fall 
  is 
  over 
  the 
  same 
  rock 
  horizon 
  as 
  its 
  predecessor. 
  Dips 
  and 
  fall 
  of 
  river 
  muc^- 
  

   exaggerated 
  

  

  PLEISTOCENE 
  GEOLOGYi 
  

   History 
  

  

  A 
  brief 
  outline 
  of 
  the 
  Pleistocene 
  history 
  and 
  its 
  relation 
  to 
  the 
  

   earlier 
  time 
  is 
  given 
  on 
  pages 
  23 
  and 
  24. 
  

  

  At 
  least 
  three 
  distinct 
  episodes 
  are 
  recognized 
  in 
  the 
  recent 
  geo- 
  

   logic 
  history 
  of 
  our 
  region. 
  These 
  are 
  (i) 
  burial 
  under 
  the 
  ice 
  

   sheet, 
  (2) 
  burial 
  under 
  standing 
  waters, 
  (3) 
  renewal 
  of 
  the 
  ex- 
  

   posure 
  to 
  the 
  atmosphere. 
  

  

  Glaciation. 
  The 
  glacial 
  theory 
  has 
  long 
  since 
  passed 
  into 
  the 
  

   category 
  of 
  accepted 
  fact. 
  That 
  our 
  area 
  has 
  been 
  subjected 
  to 
  

  

  iBy 
  H. 
  L. 
  Fairchild. 
  

  

  