370  CONTRIBUTIONS    TO   ECONOMIC    GEOLOGY,  1905. 
study  of  the  surface  conditions  did  not  reveal  appreciable  faulting.  The  fissures  and  joint 
planes  are  almost  vertical,  and  near  Colton  and  Soldier  Summit  they  bear  approximately 
N.  10°  W.  One-half  mile  west  of  Midway  station  a  fracture  zone  containing  ozokerito 
bears  N.  30°  W.  Another  half  a  mile  northeast  of  the  same  station  has  a  trend  N.  60°  W. 
In  both  instances  the  fractures  were  almost  vertical. 
Though  the  ozokerite  has  been  mined  or  prospected  at  several  points  through  a  strati, 
graphic  range  of  nearly  500  feet,  it  has  not  been  shown  that  there  is  any  systematic  variation 
in  the  thickness  of  the  deposits.  It  has  been  found  to  be  locally  variable  both  laterally 
and  vert  ically. 
NATURE  OF  THE  MINERAL. 
Three  samples  were  selected  for  laboratory  tests,  one  from  the  mine  half  a  mile  northeast 
of  Midway  sin  lion,  a  second  from  the  mine  at  Colton,  and  a  third  from  the  mine  11  miles 
north  of  Colton.  These  samples  were  subjected  to  fusion  and  solution  tests  made  in  the 
Geological  Survey  laboratory  by  Eugene  C.  Sullivan. 
The  mineral  occurring  near  Midway  and  Soldier  Summit  and  at  the  mine  in  the  town  of 
Colton  has  essentially  the  same  physical  appearance.  The  slight  variations  in  hardness 
and  color  are  not  greater  than  are  found  to  occur  at  a  single  locality.  In  places  the  ozoker- 
ite has  been  crushed  and  intimately  slickensided,  as  is  the  case  with  the  material  collected 
from  the  Colton  mine.  The  mineral  is  thereby  rendered  more  friable  than  where  such 
pressure  and  movement  of  contact  strata  has  not  occurred.  Under  ordinary  conditions 
the  mineral  is  semibrittle  and  slightly  friable,  but  a  mass  can  not  be  crushed  or  molded 
between  the  fingers.  It  cuts  easily,  somewhat  like  hard  cheese,  but  does  not  adhere  to 
the  knife.  It  is  for  the  most  part  black,  and  here  and  there  yellowish  resinous  pails  blend 
with  the  black.  In  the  Midway  mine  certain  parts  were  distinctly  fibrous  and  yellow,  as 
if  a  purer  material  had  been  blown  into  or  had  percolated  t  hrough  open  spaces  in  the  darker 
product. 
The  mineral  at  the  Midway  locality  melts  at  64°  C,  is  completely  soluble  in  boiling  ether, 
niid  has  a  faint  pel  roleum  odor.  The  Colton  product  melts  at  70°  C,  is  incompletely  soluble 
in  boiling  ether,  and  has  no  odor.  The  material  of  the  third  test,  from  the  deposits  \\ 
miles  north  of  Colton,  is  entirely  black,  has  a  pronounced  petroleum  odor,  and  can  be 
molded  in  the  lingers.  Its  melting  point  is  54°  C,  and  it  is  completely  soluble  in  boiling 
ether.  The  mineral  from  this  locality,  as  well  as  from  others  in  the  vicinity  north  and 
northeast  of  Colton,  contained  more  bitumen  or  asphalt  than  the  Midway  and  Colton 
samples,  which  accounts  for  its  lack  of  color,  softness,  and  lower  melting  point.  In  con- 
cluding his  report  on  the  tests  of  the  samples,  the  chemist  remarks  that  they  behave  like 
paraffin  on  heating,  and  are  ozokerite  or  closely  related  substances. 
DEVELOPMENT. 
The  pioneer  work  and  a  large  part  of  the  development  of  ozokerite  in  this  region  are  due 
to  the  elloits  of  Mr.  R  J.  Kroupa,  who  began  prospecting  in  the  vicinity  of  Midway  in 
1886.  Mr.  Kroupa,  who  now  lives  at  Provo  City,  Utah,  gave  material  aid  to  the  writers 
in  the  investigation  of  the  ozokerite  deposits. 
Ozokerite  has  been  exploited  commercially  at  five  and  probably  more  localities  in  this 
field.  Many  prospects  in  the  neighborhood  of  these  mines  have  been  made,  showing  the 
presence  of  the  mineral.  From  a  few  of  these  surface  workings  it  is  reported  that  a  con- 
siderable quantity  of  ozokerite  has  been  removed.  Five  mines  have  been  equipped  with 
more  or  less  complete  facilities  for  exploitation,  and  three  plants  have  been  established  for 
separating  the  product  from  the  associated  rock  materials. 
Colton  district. — One  of  the  mines  in  this  district  is  located  at  Colton.  A  shaft  is  sunk 
on  a  vertical  shear  zone  5  to  6  feet  in  width  to  a  depth  of  110  feet  and  is  equipped  with  a 
LO-horsepower  hoisting  engine.  Drifts  have  been  run  on  the  strike  of  the  fractures  at  a 
depth  of  45  feet  and  at  the  base.  The  mine  is  now  closed,  it  is  claimed,  on  account  of 
litigation.     At  the  time  of  inspection  it  was  filled  with  water  below  the  45-foot  drift.     At 
