boutwell.J     OIL    AND    ASPHALT    IN    SALT    LAKE    BASIN,    UTAH.  479 
unconsolidated  deposits.  The  location  of  the  occurrences  of  asphalt 
lends  to  suggestive  broad  geologic  considerations,  which  upon  detailed 
field  study  might  prove  to  be  of  economic  value. 
The  Promontory  asphalt  deposit  lies  in  the  general  line  of  orogenic 
deformation,  marked  by  a  well-defined  Basin  mountain  range.  Ter- 
tiary sediments  (Green  River  and  Bridger)  in  eastern  (Hah  are 
known  to  be  bituminous;  sediments  in  neighboring  regions  (believed 
from  the  description  of  their  localities  to  be  Cretaceous)  are  reported 
to  afford  seepages  of  oil,  while  in  the  Cretaceous  and  older  formations 
elsewhere  very  important  oil  fields  have  been  developed.  Tertiary 
beds  (Vermilion  Creek)  are  reported  by  geologists  of  the  Fortieth 
Parallel  Survey  to  extend  westward  beyond  the  Wasatch  Mountains, 
down  their  western  slopes  into  the  Great  Basin  just  north  of  Salt 
Lake  Cit}^.  If  this  be  true  it  is  not  improbable  that  they  may  under- 
lie the  recent  deposits  in  that  vicinity.  The  possibility  thus  arise- 
that  oil-bearing  Tertiary,  Cretaceous,  or  Carboniferous  beds  may 
occur  along  the  line  of  orogenic  deformation,  and  may  therefore  have 
been  fissured  and  opened  so  as  to  permit  the  escape  of  such  fluid  or 
semifluid  contents  as  oil  or  asphaltic  substances.  In  view  of  this 
possibility  it  is  desirable  that  exploration  should  be  made  in  regions 
where  surface  indications  are  most  favorable,  and  that  it  should  be 
ontinued  deep  enough  to  prove  or  disprove  the  presence  of  oil  or 
isphalt  in  the  consolidated  rock  bottom  of  the  basin. 
