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CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1905. 
CONCLUSION. 
In  conclusion  it  is  well  to  remark  that  the  extent ,  cither  in  thickness  or  length,  of  the  occur- 
rence of  ozokerite,  as  of  any  other  species  of  the  hydrocarbon  series  found  rilling  fissures  or 
spaces  between  broken  rock,  can  not  be  relied  on  far  beyond  the  limit  of  prospected  ground. 
Both  the  width  of  the  fissured  or  fractured  zone  and  the  occurrence  of  ozokerite  are  found  to 
be  variable.  In  no  instance  in  this  field  have  ozokerite  veins  been  reported  to  exceed  3  feet 
in  w  it  1 1  h .  Usually,  as  has  been  stated,  the  mineral  is  in  the  form  of  thin  sheets  or  veinlets 
in  fissures  or  spaces  surrounding  brecciated  rock.  It  is  evident  that  for  profitable  exploits 
tion  such  ozokerite-bearing  ground  should  contain  sufficient  mineral  wax  to  form  approxi- 
mately 10  per  cent  of  the  rock  removed  for  treatment. 
