[-58         CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   L906,   PART    I. 
in  places  a  very  remarkable  fracturing  by  which  they  appear  to  he 
on  edge,  with  a  general  north-south  strike.  The  dip,  however,  is  to 
the  west  at  angles  of  20°  to  30°. 
In  the  canyon  of  Montpelier  Creek  the  lowest  beds  exposed  are 
yellow,  sandy  limestone  and  sandstone  and  blue-gray  siliceous  lime- 
stone, which  immediately  underlie  the  phosphate  series.  The  over- 
lying limestones  generally  occur  in  massive  outcrops.  A  prominent 
spur  of  the  range  extends  nearly  to  the  town  of  Montpelier  and  is 
formed  of  limestones  and  sandstones  of  upper  Carboniferous  and 
Mesozoic  age.  The  lower  portion  of  the  upper  Carboniferous  series, 
including  the  phosphate  beds,  is  exposed  on  the  north  side  of  Mont] 
pelier  Creek,  as  shown  in  the  accompanying  section  (fig.  19). 
On  the  soul  h  side  of  Mont  pelier  ( Jreek  the  phosphate  series  is  buried 
beneath  the  detrital  slopes,  and  the  outcrops  o(  the  phosphate  beds 
Scale  in-feet 
100  200 
Fig.  i'».    Section  of  Carboniferou  north  side  of  Montpelier  Creek,  [daho. 
are  exposed  only  in  the  numerous  draws  which  cul  across  the  strike 
along  t  he  range.  Bel  ween  t  hoe  points  t  he  beds  are  not  visible  except 
wheic  exposed  by  the  large  amount  of  development  work  which  has 
been  done,  particularly  <>n  the  Waterloo  placer-mining  claim.  Their 
presence,  however,  is  indicated  by  pieces  of  float  and  the  character- 
istic darkening  of  the  soil  overlying  them.  Here  the  beds  dip  i<>  the 
west  at  a  l<»w  angle  about  l}o  to  :;o  .  They  are  remarkably  uniform 
in  character  over  a  wide  area,  rolling  slightly,  hut  showing  no  signs  of 
any  very  serious  disturbance.  Erosion  has  removed  the  upper  beds 
from  a  large  portion  of  the  -round,  leaving  extensive  areas  in  which 
the  main  phosphate  bed  i>  now  covered  by  only  a  2-foot  hand  of 
limestone  and  a  few  feel  of  shale  and  surface  detritus.  Here  and 
there  the  top  of  the  phosphate  bed  it-elf  forms  the  surface  of  the 
ground  and  in  places  the  bed  ha-  been  completely  eroded,  leaving 
only  the  hard  underlying  cherty  limestone.  The  band  of  limestone 
already  referred  to,  which  immediately  overlies  the  main  phosphate 
