248         CONTRIBUTIONS    TO    ECONOMIC    GEOLOGY,   L906,   PART    I. 
the  sandstone  that  caps  the  sand  ridges  or  mountains  overlooking  the 
vallej  .      It  dips  into  the  hills  at  angles  of  5°  to  15°. 
The  limestone  is  thus  favorably  situated  for  quarrying,  and  ii  liasj 
worked  on  a  considerable  scale  at  Blount  Springs  and  Bangor] 
(hie  quarry  between  these  two  places,  belonging  to  W.  F.  Ilarrell,  is 
now  in  operation.  This  quarry  is  an  open  working  and  the  face  id 
almost  SO  feet  high,  extending  nearly  to  the  top  of  the  outcrop  on  the 
escarpment.   The  following  is  a  section  of  the  rock  quarried: 
Section  of  Bangor  Umestom  <ii  Harrell  quarry. 
Feet. 
Gray  sem  [crystalline  limestone 28 
Dark  semicrystalline  limestone 12 
<  irav  semicrystalline  limestone 40 
The  limestone  beds  are  separated  by  thin  partings  of  carbonaceous 
shale.  Limestone  from  tl>i>  quarry  is  used  for  (lux  in  the  furnaces 
at  Birmingham  and  Bessemer. 
Other  quarries  have  been  operated  along  the  outcrop,  both  at 
Bangor  and  Blount  Springs.  The  one  al  Blount  Springs  was  oper- 
ated by  the  Sloss-Sheffield  Steel  Company.  The  composition  of  the 
limestone  Prom  this"  quarry,  which  includes  a  thickness  of  1(H)  feet  or 
more,  i->  a-  follow  s: 
.1,,  hi  analyses  of  r><in<i<>f  Umestom  from  Blount  Springs  quarry.0 
Sili<  1.05 
icicle  and  alumina  (Fe20       \1.<>    82 
Lime  carbonate    CaCO    96.  7 1 
Magnesium  carbonate    MgCO 71 
99.  32 
The  Bangor  limestone  outcrops  along  the  west  side  of  Murphree 
Valley, and  around  the  southern  point  of  Blount  Mountain,  whence  its 
outcrop  extends  along  t  lie  valley  of  Canoe  Creek  to  t  he  neighborhood 
of  Springville  and  beyond.  At  Dale  is  the  quarry  of  the  Republic  Iron 
and  Steel  Company, of  which  t  lie  following  is  an  approximate  section: 
<<//  "/'  Bangor  Umestom  <ii  /><il<  quarry. 
Feet- 
Limestone 20 
Red  shale :> 
Green  shale 5 
( iray  crystalline  limest • 25 
hark  limestone 30 
White  limestone 5 
Shale 1 
Clay 2 
Gray  limestone ' 60 
L53 
"  Analyzed  by  Henry  McCalley,  J.  I>.  Beeson,  and  J.  R    Earns.     Eckel,  E.  C,  Cemenl  materials  and 
industry  of  the  United  States:  Bull.  U.  S.  Geol.  Survey  No.  243, 1905,  p.  68. 
