CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   1903.  [bull.  225. 
furnace,  the  haulage  by  mules,  and  all  mining  is  done  by  hand.  The 
coal  shows  a  thickness  of  3i  feet  and  lies  40  feet  above  the  lower  bed. 
Rich  Hill  mine.— The  Upper  Freeport  coal  passes  below  the  sur- 
face at  the  Manion  mine,  but  it  reappears  to  the  east  near  Hastings, 
where  the  Rich  Hill  Coal  Company  has  recently  opened  a  mine  on  it. 
The  development  has  not  gone  far  enough  to  demonstrate  the  presence 
of  a  large  body  of  workable  coal  in  this  bed  in  the  Hastings  region. 
Many  of  the  companies  in  various  parts  of  the  field  report  this  coal 
as  being  of  workable  thickness  on  their  property  and  are  holding  it 
in  reserve,  as  it  is  estimated  that  the  Lower  Freeport  coal  will  be 
exhausted  before  mar^  years. 
LOWER   FREEPORT   OR    "d"   COAL. 
This  is  regarded  as  the  equivalent  of  the  famous  Moshannon  bed  of 
Clearfield  County,  and  it  is  the  most  widely  known  and  extensively 
developed  coal  in  the  field.  It  underlies  a  large  area  and  probably  it 
is  best  developed  in  the  vicinity  of  Barnesboro  and  Spangler,  where  it 
is  fast  becoming  exhausted. 
A  characteristic  feature  of  this  coal  is  a  very  persistent  binder  of 
shale,  ranging  from  1  to  3  inches  in  thickness  and  occurring  from  8  to  12 
inches  above  the  bottom  of  the  bed.  This  has  caused  erroneous  cor- 
relation by  the  miners,  for  both  higher  and  lower  coals  carry  similar 
partings  over  large  areas.  Aside  from  the  binder  the  bed  presents 
much  the  same  appearance  as  the  Upper  Freeport,  possessing  about  the 
same  hardness  and  fracture,  but  the  columnar  structure  is  probably 
more  sharply  defined  than  in  any  of  the  other  beds. 
Thickness  of  the  coal. — The  normal  thickness  of  this  bed,  based  on 
averaging  a  great  number  of  measurements  from  all  over  the  field,  is 
47^  inches,  or  nearly  4  feet.  The  greatest  measure,  61  inches,  was 
obtained  in  the  center  of  the  basin  near  Barnesboro.  The  smallest 
natural  thickness  reported  is  37i  inches.  The  following  sections  from 
various  parts  of  the  field  show  the  slight  variations  in  this  coal: 
Section  of  Lower  Freeport  coat  at  Hastings. 
Shale  roof.                                                                                                      Ft.  In. 
Coal 4  0 
Binder 0  1 
Coal 1  0 
Fire-clay  floor. 
Total 5  1 
Section  of  Lower  Freeport  coal  at  Barnesboro. 
Shale  roof.  Ft.    In. 
Bone 0  '   2 
Coal 4'    2 
Binder 0       l\ 
Coal 0     10 
Fire-clay  floor. 
Total 1    ~J\ 
