244  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1905. 
At  present  work  is  carried  on  almost  exclusively  on  the  No.  3,  or  Porter  bed,  but  a  large 
amount  of  coal  has  been  taken  from  coal  bed  No.  2  and  a  new  mine  is  being  opened  on  the 
upper  or  No.  1  bed.  At  this  mine  the  coal  is  screened  into  three  grades— lump,  nut,  and! 
slack.  The  lump  and  nut  are  sold  for  domestic  and  steam  purposes  and  the  slack,  amount- 
ing to  about  one-quarter  of  the  output,  is  sold  to  the  smelter  company  for  the  manufacture 
of  coke.  The  coke  is  of  fair  quality,  and  it  is  claimed  to  equal,  if  not  excel,  any  other  coke 
produced  in  Colorado. 
A  sample  of  this  coal  was  taken  last  summer  in  connection  with  the  coal-testing  work  at 
St.  Louis.  The  sample  was  obtained  by  making  a  cut  across  a  working  face  of  the  coal, 
including  all  of  the  coal  from  roof  to  floor.  The  sample  was  crushed  and  quartered  down  to 
com  enient  size  and  sent  in  a  sealed  can  to  the  chemical  laboratory  at  St.  Louis,  where  it  was 
analyzed  with  the  result  shown  in  analysis  No.  11  on  page  258.  According  to  this  analysis 
the  coal  is  of  a  particularly  high  grade,  being  low  in  sulphur,  moisture,  and  ash,  and  high  in 
fixed  carbon. 
The  coal  beds  of  this  group  are  also  worked  at  Hesperus,  10  miles  from  Durango,  in  the 
western  part  of  the  district.  In  this  locality  there  are  three  beds  which  seem  to  correspond 
to  those  at  Porter  and  Durango.  Two  mines  have  been  opened,  the  Hesperus  mine,  by  the 
Porter  Fuel  Company,  and  the  Ute  mine,  by  the  Ute  Coal  Company.  Roth  of  these  mines 
are  in  the  lowest  coal  bed,  which  is  believed  to  be  the  same  as  (he  Porter  bed.  The  only 
mine  in  operation  is  the  Hesperus  mine,  which  is  situated  on  the  Rio  Grande  Southern  Rail- 
road, and  practically  all  of  the  output  is  shipped  over  this  line. 
At  a  geologic  horizon  about  2,.500  feet  above  the  Mesaverde  formation  occurs  a  group  of 
coal  beds  near  the  middle  of  the  Laramie  ( ?)  formation.  The  coal  of  this  group  is  of  poorer 
quality  than  the  Porter  coal  just  described,  but  on  account  of  the  thickness  of  the  beds  it 
may  prove  to  be  of  considerable  value. 
The  best  exposure  of  this  coal  is  about  3  miles  south  of  Durango,  at  Carbon  Junction, 
formerly  known  asCarbonero,  and  from  this  place  the  coal  is  usually  known  as  theCarbonero 
coal.     It  was  once  mined  here,  and  a  part  ia!  seel  ion  at  the  now  abandoned  mine  is  as  follows: 
Section  ofCarbonero  coal  bed  near  Carbon  Junction,  2\  miles  south  of  Durango,  Colo. 
Feet. 
Terrace  gravel,  surficial 4 
i  !oal,  with  thin  shale  seams 20 
Shale,  drab 2 
Sandstone,  argillaceous 3 
Debris-covered  interval 15 
Coal,  with  thin  shale  seams 22 
Shale 4 
Sandstone 150 
The  same  coal  bed  was  formerly  worked  at  the  La  Plata  mine,  east  of  Carbon  Junction, 
where  it  has  a  thickness  and  section  similar  to  those  on  Animas  River.  When  in  opera- 
tion, this  mine  was  connected  with  the  Denver  and  Rio  Grande  Railroad  by  a  spur  from 
Arboles. 
LOS    PINOS    RIVER    DISTRICT. 
The  Los  Pinos  River  district  lies  east  of  the  Durango  district  and  extends  from  Florida 
River  eastward  across  Los  Pinos  River,  Piedra  River,  and  Rio  Nutria.  Like  the  Durango 
district,  it  lies  mostly  in  the  foothills  of  the  San  Juan  Mountains,  where  they  give  way  to 
the  plateau,  country  on  the  south.  It  contains  both  Mesaverde  and  Laramie  (?)  coal  of 
good  quality,  but,  having  no  railroad  facilities,  the  mines  are  small  and  the  output  is  limited 
to  local  demands.  The  coal  beds  of  the  Mesaverde  formation  extend  eastward  from 
Durango  across  Florida  River.  Where  they  cross  the  Florida,  a  coal  bed  of  this  group  has 
been  opened  at  the  Perkins  &  Rockwood  mine,  showing  the  following  section: 
