370  CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,  1904.         [bull.  260. 
This  seam  is  generally  overlain  by  a  coarse,  heavy  sandstone,  as  at 
Milldale  and  Brookwood,  or  by  a  conglomerate,  as  along  Hurricane 
Creek  and  its  branches.  What  is  regarded  as  this  conglomerate  or 
its  equivalent — coarse  sandstone,  with  the  coal  beneath — is  generally 
present  on  the  west  side  of  Black  Warrior  River  from  north  of  Bone 
Creek  southward  and  serves  for  the  identification  of  the  coal.  At 
Searles  and  Central  it  is  believed  that  the  Milldale  seam  forms  the 
bottom  bench  of  the  Brookwood  seam,  the  two  seams  approaching 
within  a  few  inches  of  each  other  by  the  disappearance  of  the  sand 
stone  that  separates  them  elsewhere. 
The  Johnson,  or  Carter,  seam,  as  it  is  locally  known,  is  of  impor- 
tance in  the  region  between  Milldale  and  Brookwood,  where  it  has  an 
average  thickness  of  30  inches  nearly  solid  coal.  The  following  are 
sections  from  this  region : 
Sections  of  Johnson  01   Carter  seam. 
No.  1.     Alabama  Consolidated  mine,  Hewett. 
Sandstone :  Inches. 
Coal 25  to  30 
No.  2.     Alabama  Consolidated  mine  No.  10,  Brookwood,  at  pit'? 
mouth. 
Sandstone :  Inches. 
Shale 48 
Coal 19 
Slate 1 
Coal 13^ 
Total  coal 33* 
No.  3.     Alabama  Consolidated  mine  No.  10,  Brookwood,  at  end  of 
entry. 
Sandstone :  Inches. 
Shale 48 
Coal 23 
Slate 1 
Coal 12 
. 
Total  coal 30 
The  Johnson  seam  is  everywhere  closely  overlain  by  a  massive 
sandstone,  from  which  it  is  in  places  separated  by  a  few  feet  of  shale 
In  places  the  coal  is  partly  or  wholly  lacking,  and  its  place  is  take! 
by  the  sandstone.  A  seam  that  is  apparently  the  Johnson  seam  wa 
seen  at  a  few  points  on  the  branches  of  Hurricane  Creek  west  o 
Ruhama  Church,  where  it  is  only  1  foot  or  less  thick  and  lies  in  th 
midst  of  heavy  sandstone.  The  blossom  of  a  coal,  apparently  smal 
in  sandstone  was  noted  at  several  points  on  the  ridges  between  Davi 
