CLAYS. 
CLAYS  OF  GARLAND  COUNTY,  ARK. 
By  Edwin  C.  Eckel 
General  statement. — During  the  fall  of  1905  the  writer  was  detailed,  at  the  request  of  the 
iSecretary  of  the  Interior,  to  examine  the  clays  of  the  Plot  Springs  Reservation,  Ark.,  and 
jreport  on  the  commercial  value  of  such  deposits  as  could  be  found.  In  the  course  of  the 
jfew  days  devoted  to  this  work  several  clay  deposits  in  Garland  County,  outside  the  limits 
of  the  reservation,  were  visited  and  sampled.  The  following  paper  is  a  summary  of  the-prin- 
(cipal  features  brought  out  by  this  work. 
As  the  area  covered  by  the  Hot  Springs  Reservation  lies  entirely  outside  of  the  Creta- 
ceous and  Tertiary  portion  of  Arkansas,  the  clays  to  be  found  there  represent  but  two  types: 
(1)  Paleozoic  shales,  and  (2)  recent  river  and  stream  deposits.  The  latter  group  includes 
a  few  small  clay  beds  which  in  places  have  been  worked  on  a  small  scale  for  the  manufacture 
of  common  red' brick  of  poor  grade.  The  Paleozoic  shales,  however,  by  their  leaching  and 
decay  in  place  form  a  series  of  light-colored  siliceous  clays  of  more  importance. 
The  area  within  the  reservation  was  examined  with  some  care,  and  several  developed 
clay  properties  in  other  parts  of  Hot  Springs  County  were  visited  for  comparison.  The 
localities  and  separate  deposits  are  first  described,  after  which  the  economic  features  of  the 
matter  are  summarized. 
Description  of  clay  deposits. — On  the  southeast  side  of  Hot  Springs  Mountain,  near  the 
road  crossing  its  crest,  a  series  of  light-colored  clays  is  exposed.  The  section  shows  6  to  10 
feet  of  these  clays,  mostly  light-gray  in  color,  but  with  occasional  thin  reddish  bands. 
The  clays  are  quite  free  from  coarse  sand  or  grit.  Their  strike  and  dip  are  very  variable, 
but  a  fair  average  would  probably  be  N.  70°  W.  and  25°  S. 
Samples  were  collected  from  this  locality  and  analyzed  in  the  Survey  laboratory  by  George 
Steiger,  with  the  following  results: 
Analysis  of  clays  from  Hot  Springs  Mountain. 
Silica 73. 07 
Alumina 16.  40 
Titanic  oxide 1. 09 
Iron  oxide 1. 12 
Lime 25 
Magnesia 64 
Soda 26 
Potash 2. 75 
Combined  water 4. 46 
Moisture 36 
407 
