324  CONTRIBUTIONS   TO   ECONOMIC   GEOLOGY,  1904.        [bull.  260.] 
be  recognized  by  reference  to  the  topographic  map  of  the  Brook- 
wood  quadrangle,  published  by  the  United  States  Geological  Sur- 
vey,  or   to   the   map   of  the   Cahaba    coal   field,   published   by   the! 
Alabama    Geological    Survey.     The    strike   c      this   strip    of    rocks 
presents  a  broad  curve  concave  to  the  northwest,  and  varies  from 
N.   45°   E.  to  N.  25°   E.     In  the  northeast   part  of  the  strip   till 
rocks    dip    generally   at    steep    angles    (60°    to    80°)    toward    the; 
northwest,   except   at   a   number   of  places  where  they   are  locally 
overturned  and  dip  to  the  southeast.     Three  or  four  seams  of  ore 
occur  in  the  formation  in  sees.  23,  26,  and  34,  T.  19  N.,  R.  5  W.,  butJlj 
they  are  either  too  thin  or  too  sandy  to  be  of  value.     This  port  ion  I 
of  the  field  is  comparatively  well  known,  as  its  proximity  to  the 
mining  activity  at  Bessemer  has  caused  it  to  be  fairly  well  prosll 
pected  for  ore.     Sections  of  several  outcrops  and  strippings  are  given) i 
by   McCalley.tt     Farther   southwest   this   strip   contains   ore   of  buntj 
little  value,  as  is  indicated  by  the  cut  through  the  ridge  made  bm 
the  Alabama  Mineral  division  of  the  Louisville  and  Nashville  Rail- 
road as  adapted  from  McCalle}^' 
Section  on-  the  Alabama  Mineral  division  of  the  Louisville  and  Nashville  Rail-'  \ 
road  in  A£.  i  sec.  3,  T.  21  N.,  R.  6  W. 
Ft.  in.   ) 
18.  Debris,  Fort  Payne  chert;  probably  covers  Devonian ..._  .  1 1| 
17.  Debris,  Red  Mountain  (Rockwood)  formation  along  the  railroad  for 
about 175  If 
16.  Limonite,  stratified  layer  of  yellowish  oeher  between  nodules ;  dip 
75°  to  80°  to  the  southeast 6-8  0 
15.  Loam  (?),  a  yellowish  ocherous  color,  doubtless  from  Clinton  shales_         7  0 
.14.  Red  ore,  sandy,  pinkish-brown  color 12  ill 
13.  Red  sandy  ore,  loam  (V),  about 12  0 
12.  Red  ore,  like  14 * 8  0 
11.  Shale,  yellowish  and  orange  colors,  about 60  O'j 
10.  Red  ore,  soft,  with  very  small  amount  of  pebbles  or  large  siliceous 
grains,  about 1  5 
9.  Shale,  bright  yellowish  color 5-6  0 
8.  Red  ore,  sandy  and  soft  or  well  leached 2  0 
7.  Sandstone,  yellowish  ocher  color,  about 4  C 
6.  Red  ore,  very  good,  pink,  about  vertical  on  outcrop 1  2 
5.   Sandstone,  flaggy,  yellowish  ocherous  color,  soft 9-10  C 
4.  Red  ore,  about 0  f 
3.  Sandstone  like  5,  about 25  (Ml 
2.  Debris,  Red  Mountain  (Rockwood)  formation,  though  it  may  cover 
some  I Vlham  (Chickamauga)  strata  on  northwest  side  of  narrow 
depression II 
1.  Debris,  ivib.un  (Chickamauga)  limestone -  [| 
°  McCalley,  Henry,  Report  on  valley  regions  of  Alabama  :    Alabama  Geol.  Survey,  pt.  2  i 
1897,  pp.  353-357. 
"McCalley,  op.  cit.,  pp.  467-468. 
I 
