GRAY    TRON    ORES    OF    TALLADEGA    COUNTY,  ALA.  179 
)rk  of  the  Alabama  survey  it  was  stated  that  the  "  magnetite "  or 
ay  ore  represented  a  beach  accumulation  of  black  sand,  such  as 
curs  at  many  places  along  the  seashore  at  the  present  day.  This 
■pothesis  has  persisted  practically  down  to  the  present  time.  Care- 
l  microscopic  examination,  however,  fails  to  show  that  the  grains 
d  been  water  rounded.  In  fact,  much  of  the  ore  has  been  carried 
;o  its  present  position  since  the  sedimentary  rocks  became  thor- 
ghly  consolidated.  This  fact  is  proved  by  numerous  specimens 
llected  and  preserved  by  the  United  States  Geological  Survey, 
dch  show  the  ore  occurring  on  joint  planes  of  the  quartzite  at  right 
gles  to  the  bedding.  Then,  again,  microscopic  study  shows  that 
my  of  the  grains  of  iron  ore  have  clean,  sharp  crystalline  outlines, 
dch  could  only  be  the  case  if  the  ore  had  been  formed  where  it  is 
w  found;  otherwise  the  grains  would  have  been  rolled  and  abraded 
til  little  of  their  crystalline  form  remained. 
Another  vital  objection  to  the  idea  of  beach  accumulation  of  mag- 
tite  is  the  fact  that  by  far  the  larger  portion  of  iron  is  hematite, 
cording  to  the  analysis  of  the  average  sample  already  noted, 
matite  formed  97  per  cent  and  magnetite  only  3  per  cent  of  the 
tire  iron  content  of  the  ore.  It  is  therefore  evident  that  the  ques- 
n  of  the  origin  of  the  ore  concerns  the  origin  of  hematite  rather  than 
ignetite.  Beach  accumulations  of  hematite  are  practically 
known,  so  that  it  is  necessary  to  believe  either  that  the  hematite 
s  derived  subsequently  from  magnetite  or  the  beach  accumulation 
pothesis  must  be  discarded.  Although  instances  of  alteration  of 
ignetite  into  hematite  are  known,  they  are  by  no  means  common 
der  the  conditions  which  must  have  existed  in  Talladega  County  in 
3  geologic  past.  Besides,  it  has  been  proved  that  the  hematite  was 
•rued  earlier  than  the  magnetite.  The  idea  that  these  iron  ores 
re  originally  magnetites  which  have  since  been  metamorphosed, 
dnly  through  deformation  and  consequent  reformation  of  the  dif- 
ent  minerals,  must  therefore  be  abandoned. 
It  has  also  been  suggested  that  the  ores  were  originally  deposited  in 
3  form  of  an  impure  carbonate  ore  which  was  subsequently  acted 
on  by  great  pressure,  heat,  and  moisture.  These  processes  changed 
3  ore  into  a  magnetite  and  decreased  its  volume  to  about  one-half  its 
ginal  size.  This  hypothesis  also  seems  untenable.  In  the  first 
ice  the  ore  is  not  magnetite.  But  even  neglecting  this  point  and 
bstituting  hematite  for  magnetite — for  the  theory  applies  nearly 
ually  well  for  either — there  seems  to  be  no  good  way  of  accounting 
•  the  almost  entire  lack  of  lime  either  in  the  ore  itself  or  in  the  adja- 
it  rocks.  If  lime  were  originally  present  it  must  have  gone  some- 
Lere,  and  must  have  enriched  some  region  with  exactly  the  same 
lount  of  lime  that  was  lost  by  the  iron  ores.     In  Alabama  there 
