﻿G. 
  H. 
  Stone 
  — 
  Aspkaltum 
  of 
  Utah 
  and 
  Colorado. 
  157 
  

  

  If 
  asphaltic 
  tar 
  as 
  such 
  rose 
  in 
  fissures 
  and 
  sub-aerially 
  

   poured 
  out 
  over 
  the 
  ground 
  or 
  penetrated 
  the 
  pores 
  of 
  the 
  ad- 
  

   joining 
  sediments, 
  we 
  ought 
  to 
  find 
  the 
  richest 
  areas 
  nearest 
  

   the 
  fissures. 
  But 
  if 
  oil 
  or 
  asphalt 
  rose 
  to 
  the 
  surface 
  of 
  the 
  

   lake 
  and 
  then 
  was 
  driven 
  far 
  and 
  wide 
  by 
  the 
  winds 
  and 
  waves, 
  

   the 
  larger 
  masses 
  of 
  asphalt 
  might 
  be 
  far 
  away 
  from 
  the 
  

   fissures. 
  The 
  bedding 
  and 
  other 
  structural 
  phenomena 
  would 
  

   be 
  the 
  same 
  whether 
  this 
  rose 
  from 
  the 
  marine 
  shales 
  through 
  

   fissures, 
  or 
  was 
  derived 
  from 
  the 
  primary 
  decomposition 
  of 
  the 
  

   organic 
  matter 
  buried 
  in 
  the 
  sediments 
  of 
  the 
  lake. 
  

  

  The 
  fact 
  that 
  the 
  asphalt 
  was 
  not 
  formed 
  till 
  a 
  considerable 
  

   depth 
  of 
  Tertiary 
  rocks 
  was 
  laid 
  down, 
  favors 
  the 
  hypothesis 
  

   that 
  it 
  was 
  derived 
  from 
  organic 
  matter 
  contained 
  in 
  the 
  Ter- 
  

   tiary 
  beds. 
  However 
  I 
  leave 
  the 
  matter 
  open 
  ; 
  though 
  it 
  must 
  

   be 
  admitted 
  that 
  thus 
  far 
  1 
  have 
  discovered 
  no 
  field 
  evidence 
  

   of 
  the 
  passage 
  of 
  oils 
  or 
  bitumens 
  upward 
  from 
  the 
  Cretaceous 
  

   marine 
  shales 
  to 
  form 
  the 
  asphalts 
  of 
  Tertiary 
  time. 
  

  

  2 
  Was 
  the 
  asphalt 
  derived 
  from 
  gas 
  brought 
  up 
  to 
  the 
  sur- 
  

   face 
  ? 
  Professor 
  Orton 
  in 
  the 
  work 
  cited 
  well 
  states 
  the 
  

   chemical 
  objections 
  to 
  the 
  theory 
  of 
  synthesis 
  of 
  more 
  complex 
  

   compounds 
  from 
  gas. 
  However 
  it 
  is 
  not 
  my 
  purpose 
  to 
  enter 
  

   into 
  a 
  general 
  argument, 
  only 
  to 
  note 
  the 
  bearing 
  of 
  the 
  facts 
  

   discovered 
  in 
  Colorado. 
  There 
  are 
  gas 
  springs 
  on 
  the 
  lower 
  

   White 
  River. 
  In 
  some 
  places 
  the 
  gas 
  is 
  said 
  to 
  be 
  accompanied 
  

   by 
  a 
  trace 
  of 
  petroleum, 
  but 
  there 
  is 
  no 
  proof 
  that 
  the 
  one 
  is 
  

   derived 
  from 
  the 
  other, 
  and 
  there 
  is 
  no 
  deposit 
  of 
  asphaltum 
  

   forming 
  around 
  the 
  place. 
  I 
  find 
  no 
  field 
  evidence 
  that 
  the 
  

   asphalt 
  under 
  description 
  originated 
  in 
  gas 
  coming 
  to 
  the 
  sur- 
  

   face 
  from 
  below. 
  The 
  surface 
  rocks 
  at 
  these 
  gas 
  springs 
  are 
  

   the 
  very 
  lowest 
  of 
  the 
  Green 
  River 
  and 
  uppermost 
  of 
  the 
  

   Wasatch.* 
  

  

  5. 
  Near 
  the 
  Utah 
  line, 
  on 
  the 
  head-waters 
  of 
  West 
  Salt 
  

   Creek, 
  Col., 
  is 
  a 
  field 
  of 
  sand 
  asphalt 
  which 
  contains 
  concre- 
  

   tionary 
  masses 
  of 
  the 
  sand 
  rock 
  cemented 
  with 
  lime 
  and 
  iron, 
  

   from 
  the 
  size 
  of 
  cherries 
  up 
  to 
  four 
  feet 
  in 
  diameter. 
  The 
  

   concretions 
  are 
  very 
  compact 
  and 
  impenetrable 
  and 
  are 
  free 
  

   from 
  asphalt, 
  while 
  the 
  surrounding 
  rock 
  is 
  thoroughly 
  charged 
  

  

  (through 
  the 
  pore9 
  of 
  the 
  sand) 
  before 
  it 
  became 
  so 
  hard 
  as 
  at 
  present. 
  In 
  one 
  

   place 
  a 
  large 
  field 
  of 
  the 
  asphaltic 
  sand 
  rock 
  has 
  been 
  laid 
  bare 
  by 
  erosion. 
  The 
  

   bed 
  dips 
  about 
  15°, 
  and 
  under 
  the 
  heat 
  and 
  force 
  of 
  gravity 
  has 
  flowed 
  bodily 
  

   like 
  a 
  glacier, 
  so 
  as 
  to 
  dip 
  down 
  the 
  sides 
  of 
  ravines 
  of 
  erosion 
  a 
  short 
  distance. 
  

   Some 
  have 
  described 
  this 
  as 
  over-flow 
  asphalt 
  The 
  flow 
  is 
  not 
  equal 
  throughout 
  

   the 
  mass, 
  but 
  is 
  more 
  active 
  along 
  certain 
  lines 
  of 
  fracture, 
  so 
  that 
  the 
  upper 
  

   surface 
  looks 
  like 
  an 
  exposure 
  of 
  basaltic 
  columns, 
  while 
  the 
  prisms 
  are 
  marked 
  

   one 
  from 
  the 
  other 
  by 
  depressions 
  one 
  to 
  four 
  inches 
  deep 
  that 
  are 
  in 
  some 
  cases 
  

   partly 
  filled 
  by 
  true 
  out-flow 
  asphalt 
  that 
  has 
  oozed 
  out 
  of 
  the 
  sand. 
  As 
  a 
  body 
  

   this 
  is 
  a 
  mass 
  of 
  sand 
  cemented 
  by 
  viscous 
  asphalt 
  and 
  having 
  a 
  sort 
  of 
  plastic 
  

   flow, 
  the 
  units 
  of 
  motion 
  being 
  the 
  prisms 
  except 
  at 
  the 
  prismatic 
  lines 
  where 
  the 
  

   units 
  are 
  the 
  sand 
  grains. 
  

  

  * 
  Prof. 
  A. 
  Lakes 
  of 
  Golden, 
  Colo., 
  like 
  myself, 
  found 
  no 
  oil 
  at 
  these 
  gas 
  springs. 
  

  

  