ROGUE    RIVER   VALLEY   COAL  FIELD,    OREGON.  405 
rated  by  50  feet  of  slippery  shale  and  shaly  sandstone.  The  coal  beds 
are  made  up  of  streaks  of  good  coal  locally  6  inches  thick  and  sepa- 
rated by  coaly  shale.  The  coal  breaks  out  in  blocks  and  contains  a 
considerable  percentage  of  sulphur.  The  disturbing  features  at  this 
prospect  are  irregular  masses  of  old  lavas,  which  appear  not  only  in 
all  the  entries,  but  at  various  levels  on  the  surface  and  in  bluffs  near  by 
along  the  creek.  Where  the  coal  is  in  contact  with  the  lava  the  lat- 
ter appears  to  be  the  older.  The  abundance  and  irregularity  of  these 
lava  masses  render  the  extent  of  the  coal  beds  a  matter  of  doubt. 
COAL   NEAR   ACER,   CAL. 
As  already  stated,  the  coal  belt  extends  south  through  the  Siskiyou 
Mountains  into  California,  where  several  coal  beds  have  been  reported 
near  Ager  and  one  of  them  prospected  to  a  considerable  depth  on  an 
incline  of  45°. 
SUMMARY. 
Although  coal  beds  have  been  prospected,  as  noted  above,  at  six 
localities  between  Evans  Creek  and  Ashland,  a  distance  of  40  miles, 
the  evidence  thus  far  available  does  not  indicate  the  continuity  of 
the  same  coal  beds  throughout  that  distance,  but  rather  the  develop- 
ment of  small  beds  a  few  miles  in  greatest  extent  parallel  to  the  coal 
belt  and  to  the  old  shore  line  along  which  the  vegetation  accumu- 
lated in  swamps  to  form  coal.  The  swamps  lay  at  the  base  of  the 
Klamath  Mountains  when  the  coal-bearing  beds  were  deposited  over 
the  low  flats  and  the  shallow  body  of  water  extending  to  the  northeast. 
The  most  impressive  feature  at  all  the  localities  examined  is  the 
improvement  in  the  coal  toward  the  northeast,  down  the  dip  of  the 
coal  beds  into  the  hill.  This  is  not  simply  a  matter  of  weathering, 
but  a  decided  increase  in  the  amount  of  coal  present  and  a  decrease 
in  the  amount  of  fine  sediment  washed  into  the  original  swamp  where 
the  vegetal  matter  was  accumulating.  The  farther  northeast  in 
the  swamp  the  deposits  lie,  the  farther  from  the  source  of  the  wash 
from  the  slopes  of  the  Klamath  Mountains  and  to  a  certain  extent 
the  thicker  and  purer  the  coal. 
The  age  of  the  coal-bearing  rocks  of  the  Rogue  River  valley  is  not 
yet  fully  determined.  They  contain  numerous  fossil  leaves  which  are 
now  regarded  by  Doctor  Knowlton  as  Eocene,  although  the  latest  col- 
lections from  that  region  have  not  yet  been  studied.  It  is  probable, 
however,  that  they  are  Eocene  and  of  approximately  the  same  age  as 
the  coal  of  Coos  Bay. 
For  the  present  the  coal  beds  from  Ager  to  Evans  Creek  are  only  of 
local  interest  as  a  source  of  fuel,  but  detailed  examinations  in  the 
future  may  show  these  coals  to  be  more  extensive  than  they  are  now 
supposed.  If  so,  they  may  become,  with  the  improvement  of  gas 
producers,  important  sources  of  power. 
