LIME,  MAGNESITE,  ETC 
LIMESTONE  AND  DOLOMITE  IN  THE  BIRMING- 
HAM DISTRICT,  ALABAMA. 
By  Charles  Butts. 
INTRODUCTION. 
Both  limestone  and  dolomite  are  important  from  an  economic 
standpoint  in  the  Birmingham  district.  Limestone  is  used  for  lime 
and  cement,  and  both  limestone  and  dolomite  are  expensively  utilized 
as  flux  in  iron  smelting.  Indeed,  this  fluxing  material  is  one  of  the 
three  essential  factors  in  the  great  industrial  development  of  the 
Birmingham  district,  coal  and  iron,  of  course,  being  the  other  two. 
Along  Birmingham  Valley,  from  Bessemer  to  Trussville,  ore,  coal,  and 
flux  are  to  be  had  within  a  distance  of  5  to  10  miles  from  each  other, 
and  it  is  due  to  the  proximity  of  these  three  indispensable  materials 
that  profitable  iron  making  from  the  comparatively  low-grade  ores 
of  this  region  is  possible.  This  paper  is  based  on  work  done  in  the 
field  by  Chester  W.  Washburne,  William  F.  Prouty,  E.  F.  Burchard, 
E.  M.  Dawson,  jr.,  and  the  writer.  Other  published  reports  have 
been  freely  drawn  on  for  information,  for  which  due  acknowledgment 
is  made  in  the  proper  place. 
In  this  area  there  are  three  distinct  limestone  formations  and  one 
dolomite  formation.  These  are  the  Bangor  limestone,  the  jChicka- 
mauga  (" Trenton")  limestone,  the  Knox  dolomite,  and  the  Cona- 
sauga  limestone,  the  highest  being  named  first. 
BANGOR   LIMESTONE. 
The  Bangor  limestone  is  of  Carboniferous  age  and  is  named  from 
Bangor,  Ala.,  where  it  has  been  quarried.  It  is  generally  a  semicrys- 
talline,  rather  light-gray  limestone,  varying  from  a  few  feet  to  300  feet 
or  more  in  thickness. 
This  limestone  outcrops  along  both  sides  of  Blount  Valley,  from 
Reid  station  to  Bangor  and  farther  north,  where  it  forms  a  consider- 
able part  of  the  valley  walls,  extending  up  nearly  to  the  bottom  of 
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