GRAY    IKON    ORES    OF    TALLADEGA    COUNTY,  ALA.  163 
pouth  forming  an  elongated  ringlike  mountain  known  as  Columbiana 
Mountain.  Beeswax  Creek  cuts  entirely  across  this  mountain  in  its 
■northwest  and  southeast  limbs.  The  longer  axis  of  the  ellipse  is 
northeast-southwest. 
Throughout  its  entire  extent  the  range  is  tree-covered,  and  on  its 
gentle  lower  slopes  small,  rather  poor  farms  are  located.  In  its  upper 
portions,  however,  the  slopes  are  steep  and  are  covered  with  heavy 
float  of  coarse  conglomeratic  sandstone.  The  summit  of  the  ridge  is 
almost  everywhere  formed  of  coarse  sandstone  that  breaks  into 
angular  fragments,  many  of  them  of  large  size.  The  lowland  on 
either  side  of  the  range  has  been  eroded  on  soft  rocks,  generally 
limestones  or  limy  shales.  The  limestones  have  at  many  places  a 
very  different  trend  from  the  ridge-making  rocks,  so  that  the  contact 
between  these  two  is  generally  a  fault. 
The  fact  that  the  ridges  stand  up  above  the  surrounding  country  is 
due  chiefly  to  the  protection  that  has  been  afforded  the  weaker  under- 
lying rocks  by  the  strong,  massive  quartzitic  sandstones  that  form  the 
crests  of  the  ridges.  In  the  geological  past  it  is  presumable  that  this 
whole  region  was  a  mountain-built  area.  By  long-continued  erosion, 
however,  a  nearly  continuous  plain,  practically  at  sea  level,  was 
formed  on  the  hard  and  soft  rocks  of  which  the  mountains  were  made. 
Later  this  plain  was  uplifted  and  the  rivers  again  began  their  work  of 
erosion  because  of  the  increased  slope  and  velocity  given  them  by  the 
uplift.  In  this  renewed  activity  it  is  evident  that  areas  of  weak  rocks, 
such  as  limestones  and  shales,  would  be  cut  down  and  opened  out  into 
larger  valleys  than  areas  of  harder  rocks,  such  as  the  sandstones.  The 
ridges  therefore  do  not  owe  their  height  to  "outbursts"  and  " upheav- 
als," by  which  they  were  elevated  higher  than  the  rest  of  the  country, 
but  rather  to  more  orderly,  systematic  processes  of  erosion,  such  as 
are  even  now  going  on,  and  constantly  tending  to  wear  away  the  softer 
rocks  faster  than  the  harder  ones. 
In  general  the  structure  of  the  ridge  appears  to  be  practically  the 
same  throughout  the  entire  region.  The  typical  structure  may  be 
well  exemplified  by  a  section  near  Oden  Gap.  Starting  with  the  dolo- 
mitic  limestone  of  the  broad  valley  through  which  the  Central  of  Geor- 
gia Railroad  runs,  the  rocks  have  a  slight  southerly  dip.  As  one 
approaches  the  ridge  the  dolomite  abruptly  gives  place  to  greenish 
chloritic  slates  and  schists,  which  also  have  a  southerly  dip,  at  a  much 
higher  angle  than  the  dolomite.  Higher  up  the  hill  and  generally 
nearly  at  the  top  of  the  ridge,  there  is  a  heavy  quartzitic  conglomeratic 
sandstone  with  a  southerly  dip  of  greater  inclination  than  the  slope  of 
the -ridge.  South  of  the  summit  the  slope  of  the  surface  is  not  so  steep 
as  that  of  the  north  side.  Here  there  is  a  series  of  slates,  schists,  and 
metamorphic  sandstones,  with   occasional   seams  of  iron  ore.     This 
