﻿378 
  W. 
  II 
  . 
  Twenhofel 
  — 
  Granite 
  Bowlders 
  in 
  (f 
  ) 
  

  

  evidence 
  is 
  both 
  in 
  the 
  manner 
  of 
  deposition 
  and 
  the 
  deposits 
  

   themselves. 
  Somewhere 
  near 
  the 
  headwaters 
  of 
  the 
  stream 
  

   which 
  brought 
  in 
  the 
  sediments 
  and 
  which 
  are 
  believed 
  to 
  have 
  

   been 
  to 
  the 
  south 
  or 
  southeast, 
  there 
  were 
  highlands 
  on 
  some 
  

   of 
  which 
  snow 
  and 
  ice 
  may 
  have 
  accumulated 
  to 
  form 
  glaciers. 
  

   Masses 
  of 
  ice 
  breaking 
  away 
  from 
  these 
  floated 
  clown 
  stream 
  

   to 
  become 
  stranded 
  or 
  stopped 
  in 
  quiet 
  waters 
  where 
  they 
  

   melted 
  and 
  deposited 
  the 
  debris 
  which 
  they 
  carried. 
  Murray 
  

   and 
  Hjort 
  have 
  stated 
  that 
  bowlders 
  dropped 
  from 
  floating 
  ice 
  

   take 
  position 
  in 
  the 
  muds 
  into 
  which 
  they 
  fall 
  with 
  the 
  long 
  axes 
  

   in 
  perpendicular 
  position.* 
  It 
  is 
  not 
  possible 
  to 
  apply 
  this 
  test 
  

   to 
  the 
  Rose 
  bowlders 
  since 
  erosion 
  has 
  warped 
  all 
  of 
  those 
  

   which 
  were 
  elou 
  gated 
  out 
  of 
  what 
  may 
  have 
  been 
  their 
  origi- 
  

   nal 
  positions 
  so 
  that 
  they 
  now 
  lie 
  with 
  the 
  greatest 
  areas 
  down- 
  

   ward. 
  

  

  To 
  the 
  extent 
  that 
  the 
  facts 
  are 
  available 
  it 
  appears 
  that 
  the 
  

   more 
  probable 
  view 
  of 
  the 
  position 
  of 
  the 
  bowlders 
  is 
  that 
  they 
  

   are 
  in 
  the 
  shales 
  and 
  contemporaneous 
  therewith. 
  

  

  If 
  the 
  second 
  view 
  outlined 
  above 
  be 
  correct, 
  the 
  sequence 
  

   of 
  events, 
  so 
  far 
  as 
  the 
  Rose 
  bowlders 
  are 
  concerned, 
  must 
  have 
  

   been 
  something 
  as 
  follows: 
  (a) 
  In 
  Pennsylvanian 
  times 
  the 
  

   region 
  of 
  Rose 
  was 
  on 
  a 
  broad 
  delta 
  or 
  river 
  flood 
  plain 
  on 
  

   which 
  masses 
  of 
  ice 
  becoming 
  detached 
  from 
  glaciers 
  which 
  

   lay 
  on 
  high 
  lands 
  assumed 
  to 
  have 
  been 
  situated 
  to 
  the 
  south 
  

   or 
  east 
  from 
  time 
  to 
  time 
  became 
  lodged 
  in 
  local 
  areas 
  and 
  

   melted 
  there, 
  (b) 
  Long 
  afterward, 
  probably 
  about 
  the 
  close 
  

   of 
  the 
  Permian, 
  the 
  strata 
  of 
  the 
  region 
  of 
  eastern 
  Kansas 
  were 
  

   warped 
  and 
  numerous 
  low 
  anticlinal 
  structures 
  were 
  developed, 
  

   one 
  of 
  which 
  involved 
  the 
  strata 
  containing 
  the 
  Rose 
  bowlders. 
  

   (c) 
  A 
  long 
  period 
  of 
  erosion 
  followed. 
  The 
  anticlinal 
  struc- 
  

   ture 
  gave 
  erosion 
  favorable 
  points 
  of 
  attack 
  which 
  led 
  to 
  the 
  

   rapid 
  removal 
  of 
  the 
  less 
  resistant 
  strata 
  so 
  that 
  the 
  area 
  of 
  

   structural 
  elevation 
  became 
  from 
  time 
  to 
  time 
  a 
  topographic 
  

   depression, 
  these 
  times 
  coinciding 
  with 
  the 
  appearance 
  of 
  weak 
  

   strata 
  at 
  the 
  surface. 
  The 
  LeRoy 
  shales 
  and 
  sandstones 
  

   constitute 
  one 
  of 
  the 
  weak 
  members 
  and 
  they 
  were 
  removed 
  to 
  

   the 
  bowlders 
  whose 
  comparative 
  resistance 
  retarded 
  erosion. 
  

   When 
  the 
  Stanton 
  limestone 
  was 
  reached, 
  the 
  streams 
  followed 
  

   it 
  down 
  the 
  structural 
  slope 
  and 
  thus 
  was 
  developed 
  the 
  valley 
  

   which 
  practically 
  surrounds 
  the 
  Rose 
  hill. 
  

  

  The 
  relation 
  that 
  the 
  Rose 
  bowlders 
  bear 
  to 
  the 
  occurrence 
  

   of 
  granitic 
  material 
  in 
  the 
  Zeanclale 
  wells 
  is 
  still 
  problemat- 
  

   ical. 
  It 
  may 
  be 
  that 
  the 
  latter 
  reached 
  its 
  position 
  in 
  the 
  

   same 
  manner 
  as 
  did 
  the 
  bowlders 
  at 
  Rose. 
  Evidence, 
  however, 
  

   has 
  lately 
  come 
  to 
  the 
  writer 
  from 
  many 
  sources 
  that 
  granitic 
  

  

  * 
  Murray 
  and 
  Hjort, 
  Depths 
  of 
  the 
  Ocean, 
  London, 
  1912, 
  p. 
  207. 
  

  

  