﻿Gould 
  — 
  Phases 
  of 
  the 
  Dakota 
  Cretaceous 
  in 
  Nahraska. 
  431 
  

  

  hard, 
  fine-grained, 
  quartzitic 
  sandstone. 
  The 
  color 
  is 
  light 
  

   gray 
  becoming 
  reddish 
  on 
  exposure. 
  This 
  quartzite 
  contains 
  

   an 
  abundant 
  dicotyledonous 
  flora, 
  also 
  some 
  conifers, 
  probably 
  

   Sequoia. 
  The 
  ledge 
  is 
  quarried 
  and 
  makes 
  an 
  excellent 
  build- 
  

   ing 
  stone, 
  but 
  it 
  is 
  in 
  bad 
  repute 
  among 
  local 
  stone 
  masons, 
  

   because 
  of 
  the 
  fact 
  that 
  it 
  is 
  too 
  hard 
  to 
  be 
  dressed. 
  It 
  differs 
  

   from 
  anything 
  seen 
  elsewhere 
  in 
  the 
  State 
  except 
  somewhat 
  

   similar 
  ledges 
  found 
  near 
  the 
  old 
  mission 
  on 
  the 
  Omaha 
  Reser- 
  

   vation 
  and 
  along 
  the 
  bluffs 
  to 
  the 
  north, 
  although 
  quartzite 
  

   bowlders 
  similar 
  in 
  character 
  are 
  found 
  in 
  Saline 
  and 
  McPher- 
  

   son 
  counties, 
  Kansas. 
  

  

  Another 
  feature 
  of 
  the 
  Dakota 
  in 
  Nebraska 
  may 
  be 
  observed 
  

   along 
  the 
  Platte 
  River 
  near 
  Louisville 
  and 
  Cedar 
  Creek. 
  The 
  

   lowest 
  formations 
  here 
  exposed 
  are 
  the 
  Upper 
  Carbonifer- 
  

   ous 
  limestones 
  and 
  shales. 
  Upon 
  these 
  the 
  Dakota 
  rests 
  uncon- 
  

   formably 
  and 
  the 
  whole 
  is 
  covered 
  as 
  elsewhere 
  by 
  the 
  loess 
  

   and 
  drift. 
  The 
  pre-Cretaceous 
  erosion 
  was 
  not 
  only 
  very 
  con- 
  

   siderable 
  but 
  also 
  very 
  irregular. 
  The 
  hills 
  of 
  the 
  old 
  Carbon- 
  

   iferous 
  rocks 
  upon 
  which 
  the 
  Dakota 
  was 
  deposited 
  were 
  prob- 
  

   ably 
  higher 
  and 
  the 
  hollows 
  deeper 
  than 
  those 
  in 
  the 
  same 
  

   region 
  to-day. 
  It 
  was 
  in 
  one 
  of 
  these 
  eroded 
  hollows, 
  proba- 
  

   bly 
  the 
  bed 
  of 
  an 
  ancient 
  Dakota 
  river, 
  that 
  there 
  was 
  depos- 
  

   ited 
  an 
  immense 
  amount 
  of 
  coarse 
  sand 
  and 
  gravel. 
  This 
  

   forms 
  the 
  gravel 
  pits 
  near 
  Cedar 
  Creek 
  and 
  Springfield. 
  

  

  In 
  the 
  gravel 
  bed 
  a 
  mile 
  west 
  of 
  Cedar 
  Creek 
  a 
  typical 
  

   exposure 
  may 
  be 
  seen. 
  A 
  spur 
  from 
  the 
  B. 
  & 
  M. 
  railroad 
  

   runs 
  along 
  the 
  base 
  of 
  the 
  hill 
  up 
  to 
  the 
  quarry. 
  The 
  lower 
  

   fifteen 
  or 
  twenty 
  feet 
  consist 
  of 
  an 
  extremely 
  hard 
  conglom- 
  

   erate 
  usually 
  cross-bedded. 
  The 
  pebbles 
  composing 
  this 
  con- 
  

   glomerate 
  are 
  smooth, 
  water-worn, 
  usually 
  white 
  or 
  yellowish 
  

   quartz. 
  They 
  vary 
  from 
  the 
  size 
  of 
  a 
  walnut 
  to 
  a 
  very 
  fine 
  

   sand. 
  This 
  part 
  of 
  the 
  ledge 
  is 
  not 
  quarried, 
  but 
  forms 
  the 
  

   floor 
  of 
  the 
  portion 
  above, 
  which 
  is 
  removed. 
  

  

  The 
  upper 
  part 
  consists 
  of 
  similar 
  material 
  with 
  the 
  impor- 
  

   tant 
  difference 
  that 
  it 
  is 
  much 
  more 
  loosely 
  cemented. 
  The 
  

   pebbles 
  are 
  usually 
  somewhat 
  smaller 
  and 
  there 
  are 
  some 
  

   layers 
  of 
  rather 
  fine 
  sand 
  and 
  occasionally 
  the 
  characteristic 
  

   ironstone 
  concretions 
  which 
  are 
  always 
  present 
  in 
  the 
  Dakota. 
  

   This 
  second 
  member 
  is 
  thirty 
  to 
  forty 
  feet 
  thick 
  and 
  is 
  exca- 
  

   vated 
  for 
  nearly 
  a 
  quarter 
  of 
  a 
  mile 
  along 
  the 
  side 
  of 
  the 
  hill. 
  

   In 
  many 
  places 
  it 
  is 
  so 
  loosely 
  cemented 
  that 
  it 
  is 
  removed 
  

   with 
  a 
  team 
  and 
  scraper, 
  not 
  even 
  a 
  plow 
  being 
  necessary 
  to 
  

   remove 
  the 
  material. 
  The 
  gravel 
  is 
  used 
  for 
  railroad 
  ballast 
  

   and 
  the 
  conglomerate, 
  known 
  locally 
  by 
  the 
  expressive 
  name 
  of 
  

   " 
  peanut 
  rock," 
  is 
  employed 
  as 
  riprap 
  and 
  filling 
  material 
  for 
  

   bridges. 
  

  

  