﻿248 
  . 
  Scientific 
  Intelligence. 
  

  

  The 
  surface 
  of 
  the 
  basaltic 
  plateau 
  is 
  covered 
  with 
  residual 
  soil, 
  

   which 
  has 
  an 
  average 
  depth 
  of 
  60 
  to 
  80 
  feet 
  over 
  thousands 
  of 
  

   square 
  miles. 
  The 
  soil 
  is 
  exceedingly 
  fine, 
  dark 
  brown 
  or 
  black 
  

   in 
  color 
  and 
  of 
  wonderful 
  fertility. 
  This 
  is 
  the 
  soil 
  of 
  the 
  cele- 
  

   brated 
  wheat 
  lands. 
  The 
  sub-soil 
  is 
  fine, 
  light 
  yellowish 
  in 
  color, 
  

   without 
  stratification, 
  and 
  in 
  many 
  localities 
  traversed 
  by 
  minute, 
  

   irregular, 
  but 
  in 
  general 
  vertical 
  tubes. 
  In 
  many 
  ways 
  this 
  sub- 
  

   soil 
  resembles 
  loess. 
  Its 
  origin 
  from 
  the 
  disintegration 
  and 
  decay 
  

   of 
  the 
  underlying 
  basalt 
  is 
  clearly 
  manifest. 
  

  

  Topographically 
  the 
  lava-covered 
  region 
  presents 
  great 
  diversity. 
  

   In 
  the 
  Blue 
  mountains 
  there 
  is 
  an 
  intricate 
  series 
  of 
  sharp-crested 
  

   ridges 
  separated 
  by 
  a 
  labyrinth 
  of 
  canyons, 
  having 
  in 
  general 
  a 
  

   depth 
  of 
  about 
  3000 
  feet. 
  Between 
  the 
  Blue 
  mountains 
  and 
  

   Snake 
  river 
  on 
  the 
  north 
  there 
  are 
  broad 
  remnants 
  of 
  the 
  nearly 
  

   level 
  plateau 
  separated 
  by 
  narrow 
  steep-sided 
  canyons, 
  in 
  general 
  

   2000 
  feet 
  deep. 
  North 
  of 
  Snake 
  river 
  there 
  is 
  a 
  vast 
  area 
  with- 
  

   out 
  deep 
  canyons, 
  but 
  diversified 
  by 
  short 
  hills, 
  from 
  50 
  to 
  80 
  

   feet 
  high, 
  none 
  of 
  which, 
  however, 
  rise 
  above 
  a 
  certain 
  general 
  

   level. 
  Along 
  the 
  eastern 
  portion 
  of 
  this 
  hilly 
  plateau 
  or 
  rolling 
  

   prairie, 
  as 
  it 
  was 
  before 
  cultivation 
  began, 
  there 
  are 
  a 
  few 
  promi- 
  

   nent 
  island-like 
  buttes 
  of 
  quartzite, 
  which 
  rise 
  through 
  the 
  basalt. 
  

  

  Among 
  the 
  details 
  noted 
  in 
  the 
  Columbia 
  lava 
  are 
  certain 
  hori- 
  

   zontal 
  joints 
  which 
  cut 
  the 
  vertical 
  columns 
  of 
  basalt 
  and 
  in 
  some 
  

   cases 
  may 
  be 
  traced 
  for 
  several 
  miles. 
  The 
  large 
  vertical 
  columns 
  

   of 
  lava 
  when 
  weathered, 
  occasionally 
  show 
  that 
  they 
  are 
  composed 
  

   of 
  small 
  horizontal 
  columns 
  or 
  prisms, 
  which 
  radiate 
  from 
  a 
  con- 
  

   fusedly 
  jointed, 
  central 
  core. 
  The 
  joints 
  which 
  bound 
  the 
  large 
  

   vertical 
  columns 
  furnished 
  the 
  cooling 
  surfaces 
  for 
  the 
  rocks 
  they 
  

   enclose. 
  The 
  bases 
  or 
  ends 
  of 
  the 
  radiating 
  columns 
  are 
  fre- 
  

   quently 
  revealed 
  on 
  the 
  surfaces 
  of 
  the 
  slightly 
  weathered 
  vertical 
  

   columns 
  by 
  a 
  net-work 
  of 
  lines 
  resembling 
  shrinkage 
  cracks. 
  

  

  A 
  report 
  on 
  the 
  observations 
  outlined 
  above 
  will 
  be 
  published 
  

   by 
  the 
  U. 
  S. 
  Geological 
  Survey. 
  

  

  2. 
  Geologic 
  Atlas 
  of 
  the 
  United 
  States 
  Yellowstone 
  National 
  

   Park, 
  Folio, 
  No. 
  30, 
  XT. 
  S. 
  Geol. 
  Surv., 
  1896. 
  — 
  It 
  seems 
  safe 
  to 
  

   say 
  that 
  probably 
  no 
  other 
  one 
  of 
  the 
  atlas 
  sheets 
  issued 
  by 
  the 
  

   Geological 
  Survey 
  will 
  command 
  more 
  attention 
  than 
  this. 
  The 
  

   National 
  Park 
  has 
  become 
  so 
  widely 
  known 
  and 
  its 
  marvels 
  are 
  

   so 
  directly 
  conducive 
  to 
  geological 
  inquiry, 
  that 
  anything 
  of 
  a 
  

   nature 
  to 
  be 
  useful 
  to 
  the 
  general 
  public 
  a3 
  well 
  as 
  to 
  scientific 
  

   men 
  will 
  certainly 
  be 
  appropriated 
  with 
  eagerness, 
  and 
  soon 
  put 
  

   to 
  practical 
  use. 
  

  

  The 
  present 
  atlas 
  contains 
  a 
  topographic 
  map 
  of 
  the 
  park 
  on 
  

   the 
  scale 
  of 
  1 
  : 
  125,000, 
  i. 
  e. 
  two 
  miles 
  to 
  an 
  inch, 
  in 
  four 
  sheets. 
  

   The 
  triangulation 
  and 
  topography 
  of 
  these 
  maps 
  is 
  by 
  J. 
  H. 
  

   Renshawe, 
  H. 
  S. 
  Chase, 
  F. 
  Tweedy, 
  W. 
  H. 
  Leflingwell, 
  and 
  S. 
  A. 
  

   Aplin, 
  Jr. 
  

  

  The 
  geological 
  maps 
  are 
  also 
  four 
  in 
  number, 
  corresponding 
  to 
  

   the 
  topographic 
  maps 
  above. 
  The 
  geology 
  is 
  by 
  Arnold 
  Hague, 
  

   J. 
  P. 
  Iddings 
  and 
  W. 
  H. 
  Weed, 
  the 
  former 
  being 
  in 
  charge 
  of 
  

  

  