CLINTON    ORES    OF    BIRMINGHAM    DISTRICT,  ALABAMA.  139 
Ft. 
in 
[Ore 
11 
1 
Sandstone,  gray 
2 
5 
Shale,  ferruginous.  . .  „ 
8 
Ore,  limy 
2 
5 
Iron  ore  (Big  seam  i;  top  1 1  feet  minable  « 
Sandstone,  highly  fer- 
ruginous  . . 
4 
8 
Sandstone,     mottled, 
highly    ferruginous 
and  fossil  if  erous  .... 
1 
3 
Calcareous  rock,  gray,  with  sandstone  and  shale  interstratified 
30 
0 
Bottom  of  formation  probably  within  35  feet. 
246     4 
Section  of  Rockwood  formation  as  shown  by  core  from  diamond  drill  at  Big  Spring,  in 
SE.  |  SE.  I  sec.  34,  T.  21  S.,  R.  6  W. 
Ft.    in. 
Limestone,  decomposed  (Fort  Payne). 
Limestone,  hard 2  1 
Sandstone,  reddish 35  0 
Limestone  (?),  impure,  with  shale  streak 27  9 
Ferruginous  rock,  red,  mottled 2-3 
Limestone  (?),  with  mottled  red  streaks,  and  shale 25  (i 
Limestone  (?),  gray,  "marbleized  " 1  11 
Limestone  (?),  gray,  "marbleized,"  fossil iferons 8  2 
Limestone  (?),  gray,  "marbleized,"  with  liver-colored  spots 7  6 
Limestone  and  shale  alternating 16  0 
Sandstone,  dark  brown 2  6 
Sandstone,  laminated,  ferruginous 29  0 
Shale,  gray,  sandy 32  10 
Ferruginous  rock,  streaked 26  3 
[ Ore,  soft,  no  core 3  9 
Iron  ore  (horizon  J  a      A    ■,  ■  -,  ,     ,.  .  1ri 
,     .                    Sand,  highly  ferruginous,  no  core 4  10 
of  Big  seam,)      [^  ^  with  ghale  stn,aks _  _  ±  u 
Iron  ore,  fossil  if  erous 3  7 
Limestone  (?),  gray,  impure,  streaked  with  flint 48  8 
Sandstone,  red  streaked 5  0 
Limestone,  with  hard  black  flint  (Chickamauga). 
284     6 
The  foregoing  sections  show,  besides  the  variation  in  details  of  the 
rmation,  the  relations  of  the  several  ore  beds.  Four  beds  have  been 
cognized  and  named  by  the  miners.     These  are  all  shown  in  section 
but  in  the  other  sections  one  or  more  of  them  have  not  been  recog- 
zed.  The  following  summary  shows  the  salient  features  of  these 
•e  beds,  commencing  with  the  uppermost : 
DESCRIPTION  OF  THE  ORE  SEAMS. 
Hickory  Nut  seam. — This  seam  comprises  3  to  5  feet  of  sandy  ore 
j  ferruginous  sandstone  characterized  by  a  great  abundance  of 
entarnerus  oblongus,  fossils  which  resemble  hickory  nuts  incased  in 
