SOUTHERN    RED    HEMATITE    IN    METALLIC    PAINT.  431 
paining  by  hand  and  of  haulage  by  wagon  to  the  nearest  railroad. 
Ordinary  grades  of  iron  ore,  such  as  are  smelted  in  the  district,  are  not 
suitable  for  paint  manufacture,  and  therefore  they  can  not  compete 
with  the  more  expensive  material  here  considered,  although  a  small 
amount  of  high-grade  ore  that  would  otherwise  be  smelted  is  sold  by 
the  iron  producers  to  paint  makers  on  account  of  the  good  price  it 
commands. 
Most  of  this  ore  that  is  used  for  paint  is  ground  by  mills  at  Chatta- 
nooga, but  a  part  of  it  goes  to  Birmingham.  The  paints  made  are  the 
reds  and  dark  browns,  and  a  considerable  quantity  of  the  ground  oxide 
is  sold  for  coloring  sand-lime  bricks  and  mortars  for  pressed-brick 
work. 
Geologic  maps  of  the  Chattanooga  and  Ringgold  quadrangles  show 
the  distribution  of  the  Rockwood  ore-bearing  formation  in  this  region. 
These  maps  have  been  published  in  folios  Nos.  6  and  2,  respectively, 
of  the  Geologic  Atlas  of  the  United  States,  issued  by  the  United  States 
Geological  Survey,  and  are  available  in  many  public  libraries  and  in 
the  offices  of  many  mining  companies.  To  persons  familiar  with  the 
region  the  beds  containing  ores  of  value  for  iron  making  are  fairly  well 
known,  but  much  of  the  territory  intervening  between  the  iron-mining 
centers  has  never  been  prospected  with  reference  to  the  value  of  the 
ores  for  paint  manufacture. 
GEOLOGIC   RELATIONS   AND   DEVELOPMENT. 
GEORGIA. 
Wildwood. — Along  the  west  base  of  Lookout  Mountain  extends  the 
anticlinal  Lookout  Valley.  On  both  sides  of  this  valley  is  exposed  the 
Rockwood  formation,  with  its  strata  dipping  away  from  the  axis.  In 
Lookout  Valley  this  formation  consists  of  about  600  feet  of  calcareous 
shale,  with  some  beds  of  blue  limestone  and  fossiliferous  hematite. 
Above  the  Rockwood  and  separated  from  it  by  a  few  feet  of  black 
Chattanooga  shale  lies  the  Fort  Payne  chert;  below  the  Rockwood  is 
the  Chickamauga  limestone.  The  Fort  Payne  chert  has  offered  greater 
resistance  to  erosion  than  the  adjacent  rocks,  and  its  base  forms  the 
crest  of  a  ridge  on  either  side  of  Lookout  Valley,  with  the  Rockwood 
shale  on  the  inner  slopes  of  the  ridges.  The  Alabama  Great  Southern 
main  line  traverses  this  valley  at  distances  of  a  quarter  to  half  a  mile 
from  the  eastern  ridge. 
The  eastern  ridge,  particularly  at  New  England,  furnished  soft  iron 
ore  to  Chattanooga  furnaces  for  many  years,  but  now  the  ore  obtain- 
able by  trenching  or  stripping  has  become  exhausted  and  mining 
activities  are  for  the  most  part  temporarily  suspended.  At  Wild- 
wood,  however,  where  the  soft  ore  has  been  found  suitable  for  paint 
manufacture;  there  is  still  some  ore  available  for  that  purpose,  part  of 
