CEMENT  RESOURCES  OF  NORTHEAST  MISSISSIPPI. 
By  A.  F.  Ckider. 
The  Selma  formation  of  the  Cretaceous  is  a  (hick  scries  of  chalks, 
chalky  limestones,  and  more  or  less  limy  clays,  which  are  well  exposed 
in  northern  and  eastern  Mississippi.  Much  of  this  chalk  is  admir- 
ably adapted  for  use  as  a  raw  material  in  Portland-cement  manufac- 
ture, and  in  Alabama  a  cement  plant  has  been  in  operation  for  some 
years,  using  chalk  from  the  Selma  formation  and  an  overlying 
residual  clay. 
The  Selma  chalk  occupies  much  of  the  counties  of  Noxubee, 
Lowndes,  Oktibbeha,  Clay.  Monroe,  Chickasaw,  Lee,  Prentiss,  and 
Alcorn,  and  smaller  portions  of  adjoining  counties. 
Thickness. — The  Selma  chalk  attains  its  maximum  thickness  in 
central  Alabama,  reaching  a  total  of  about  1,200  feet.  Westward  it 
decreases  slightly  in  thickness,  the  well  at  Livingston,  Sumter  County, 
Ala.,  giving  a  total  of  930  feet,  while  the  Avell  at  Starkville,  Oktib- 
beha County,  Miss.,  taken  in  connection  with  surrounding  outcrops, 
indicates  a  thickness  of  at  least  700  feet.  As  the  belt  turns  north- 
ward toward  Tennessee,  the  Selma  formation  decreases  rapidly  in 
thickness,  while  at  the  same  time  the  limestone  beds  contained  in  the 
formation  become  fewer  and  thinner,  until  in  Tennessee  the  Selma 
is  a  thin  series  of  somewhat  calcareous  clays,  with  only  occasional 
beds  of  chalk. 
Stratigraphy. — Owing  to  the  rapidity  with  which  it  disintegrates 
when  exposed  to  atmospheric  action,  surface  outcrops  give  com- 
paratively little  information  in  regard  to  the  stratigraphy  of  the 
Selma  formation. 
Fortunately  a  very  precise  section  of  the  Selma  chalk,  taken  at 
a  point  where  it  is  almost  of  maximum  thickness,  is  in  existence. 
This  is  embodied  in  the  record  of  a  well  drilled  at  Livingston,  Sum- 
ter County,  Ala.,  and  is  quoted  by  Dr.  E.  A.  Smith  in  his  Report 
on  the  Geology  of  the  Coastal  Plain  of  Alabama,  pages  277-278. 
The  well  was  located  just  south  of  the  boundary  between  the  Selma 
and  Ripley  formations,  and  reached  a  depth  of  1,062  feet,  so  that  it 
passed  through  the  entire  thickness  of  the  Selma  chalk  and  into  the 
underlying  Eutaw  formation. 
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