CLAYS    OF    GARLAND    COUNTY,    ARK. 
409 
The  other  large  opening  is  about  3,000  feet  west  and  shows  10  feet  of  light-gray  clay  over- 
ain  by  5  or  6  feet  of  thin  sandstones  with  thinner  interbedded  layers  of  clay. 
Analyses  of  these  clays  follow:  A  was  collected  from  the  principal  east  opening,  B  from 
he  westernmost  pit.  Both  of  these  were  analyzed  by  George  Steiger  in  the  Survey 
aboratory. 
Analyses  of  clays  from  Cedar  Mountain. 
A. 
B. 
74.  55 
13.68 
.73 
1.27 
.20 
72.  06 
15.31 
.95 
1.24 
.17 
Magnesia 
Soda 
Potasb 
Combined  water 
Moisture 
A. 
2.03 
.10 
3.84 
3.63 
.77 
2.26 
.15 
4.  53 
3.50 
.48 
Uses  of  the  clays. — So  far  as  known  the  clays  which  occur  within  the  limits  of  the  reserva- 
tion have  never  been  utilized  for  any  purpose.  For  this  reason  several  opened  deposits  out- 
side of  the  reservation  were  visited  and  sampled,  and  the  information  thus  gained  is  pre- 
sented in  this  part  of  the  report. 
When  the  analyses  of  all  these  clays  are  grouped  together,  as  in  the  following  table,  it  is 
seen  that  they  are  very  closely  alike  in  composition: 
Analyses  of  clays,  Garland  County,  ArJc. 
Silica  (Si02) 
Alumina  (A1203)  . . . 
Titanic  oxide  (Ti02) 
Iron  oxide  (Fe203) . . 
Lime  (CaO) 
Magnesia  (MgO) 
Soda  (Na20) 
Potash  (K20) 
Water+  (100°  C.) . . . . 
Water- (100°  C.).... 
73.07 
16.40 
1.09 
1.12 
.25 
.64 
.26 
2.75 
4.46 
.36 
70.31 
17.27 
1.00 
1.35 
.23 
.91 
.26 
3.51 
4.36 
73.96 
14.54 
.34 
2.17 
.15 
.49 
.80 
2.64 
3.76 
1.36 
70.29 
16.74 
.64 
2.03 
.10 
1.50 
.08 
2.76 
5.00 
1.12 
74.55 
13.68 
.73 
1.27 
.20 
2.03 
.10 
3.84 
3.63 
.77 
72.00 
15.  31 
.95 
1.24 
.17 
2.26 
.15 
4.53 
3.50 
1.  Hot  Springs  Mountain,  on  reservation. 
2.  North  Mountain,  on  reservation. 
3.  Sugar  Loaf  Mountain,  on  edge  of  reservation. 
4.  Arthur  Furr's  pits,  near  waterworks. 
5.  East  pit,  Worthington  property,  Mountain  Valley. 
6.  West  pit,  Worthington  property,  Monntain  Valley. 
Specimens  collected  by  E.  C.  Eckel,  and  analyzed  in  the  laboratory  of  the  United  States  Geological 
Survey  by  George  Steiger. 
A  fact  which  is  not  brought  out  by  analysis  is  that  they  differ  greatly  in  the  amount  of 
sand  contained,  and  this  would  have  to  be  taken  into  account  if  any  attempt  should  be  made 
to  use  them.  For  present  purposes,  however,  the  analyses  are  sufficiently  serviceable. 
Such  clays  can  be  used  satisfactorily  for  the  following  products:  (a)  pressed  brick  or  flooring 
tile,  (b)  second-grade  fire  brick,  (c)  body  for  art  pottery. 
