144 
ONTEIBUTIONS    TO    ECONOMIC    GEOLOGY,  l!MMi,  PART    I. 
of  this  bench.  The  lower  bench  of  the  Big  seam  has  dwindled  down 
to  4  or  5  feet  in  thickness  and  is  generally  composed  of  alternating 
thin  strata  of  ore  and  shale.  The  Irondale  scam  evidently  has  not 
been    recognized    here.     Three   miles   farther   southwest   the    seams 
show  the  following  section 
Character  of  Big  and  Irondale  (?)  seams  at  mouth  of  Potter  slope  No.  I ,  Tennessee  CoaM 
Iron  an</  Railroad  Company,  SE.  \  sec.  21,  T.  19  S.,  R 
II 
Strata. 
Shale. 
Big  seam 
<  ip  .  solid,  mined . 
Shale 
Sandstone,  shalj .  ferruginous. . 
Ore 
Shale 
Sandstone  with  shaly  partings 
Shale 
i  [ori  son  of  I  rondale  seam  i " 
i  >iv.  sandy,  lean,  with  shale  pa  rt- 
ings. 
Thickne 
ss. 
Ft 
in 
8 
n 
1 
i. 
'.' 
3 
1 
1 
6 
3 
n 
1 
(i 
Character. 
Soft  ore:  Metallic  iron,  i;  ,    per  cent;  i 
24 ±   per  cent ;   lime,  0,80  I     per  cent. 
mined  at  present. 
Lower  bench. 
isolubla 
Soft  ore 
ORE  BEDS  ON  WEST  RED  MOUNTAIN. 
On  West  Red  Mountain  the  rocks  dip  at  high  angles  and  appear 
not  to  carry  valuable  scams  of  iron  ore  throughout  the  middle  of  the 
district.  At  the  extreme  ends  of  the  district,  however,  the  dips  are 
more  gentle,  and  workable  seams  have  been  discovered,  for  instance,  ' 
at  Compton  and  Dudley.  The  two  following  sections  of  the  Kock- 
wood  formation,  measured  by  Charles  Butts,  show  the  genera 
character  of  the  beds  in  the  northeast  half  of  West  Red  Mountain. 
Comparison  of  these  sections  with  those  made  on  livd  Mountain 
(pp.  136-139)  indicates  that  t  he  format  ion  t  hickens  to  the  northwest. 
The  measured  thicknesses  have  been  corrected  for  dip,  and  the 
figures  represent  the  computed  actual  thickness  of  the  beds. 
Section  of  Rockwood formation  on  West  Red  Mountain,  at  Cunningham  (lap,  in  SW.  |j 
sec.  10,  T.  16  S.,  It.  !  W. 
Ft.     in. 
(  lnii  debris  i  Fori  Payne). 
Sandstone,  highly  ferruginous,  exposed  in  prospect  pit 5  o 
Unexposed 39  0 
Sandstone 7  10 
tin  sxposed 31  0 
Sandstone 2  0 
Unexposed 15  8 
Sandstone,  in  massive  beds 31  (> 
Unexposed 15  0 
Sandstone 4  0 
Unexposed 23  9 
