310  CONTRIBUTIONS    TO   ECONOMIC    GEOLOGY,  1906 ,  PART    I. 
The  following  are  some  chemical  and  physical  tests  made  upon  clays 
in  this  vicinity : 
Chemical  and  physical  tests  of  clays  from  beds  near  Mclntyrc  and  Gordon,  Ga. 
1. 
2. 
3. 
4. 
5. 
6. 
Moisture  at  100°  C  . . . 
0.S9 
14.  10 
43,57 
39.  34 
.72 
None. 
.10 
.05 
.  10 
L.  61 
«»7 
(a) 
0.90 
[?,.  -17 
44. 22 
38.40 
1.70 
Trace. 
Trace. 
Trace. 
.28 
1.48 
1.98 
0.21 
14.52 
43.  61 
40.  42 
.70 
.37 
Alumina 
Fe  rric  oxide 
Lime 
.83 
Trace. 
""36: 
1.90 
3G 
35 
36 
a  Unaffected  al  3000°  F. 
1.  Semihard  fire  clay,  used  locally  as  a  building  stone,  '■'>  miles  east  of  Mclntyre;  E.  Everhart,  analyst. 
2.  Same  locality  as  above,  iron-st  aiiied  soft  kaolin,  4  to  15  Eee1  thick;    E.  Everhart,  analyst. 
A.  White  friable  clay.  1!  miles  south  of  Gordon;  clay  bed  12  I-  feel  I  hick. 
4.  Cream-colored,  fine-grained  bard  clay,  3 miles  south  of  Gordon;  clay  bed  :;<>  feet  thick. 
5.  Clay  from  bed  r.  miles easl  of  Lewiston. 
ti.  Clay  from  bed  1  mile  south  of  Irwinton.     A  very  pureclay,  hut  cracks  when  burned. 
GIBSON. 
Gibson  is  on  the  Augusta  Southern  Railroad,  50  miles  southwest  of 
Augusta.  Large  undeveloped  deposits  of  both  kaolin  and  fire  clay 
occur  here.  The  clays  are  in  the  same  geologic  position  as  the  clays 
farther  southwest — in  contact  with  Tertiary  strata  and  at  the  base  of 
Tertiary  ridges  and  hills.  They  are  overlain  by  loose  sand,  green  and 
drab  clays,  and  occasionally  by  thin  beds  of  limestone.  Three  miles 
east  of  Gibson  there  is  a  kaolin  deposit  that  varies  in  thickness  from 
18  to  30  feet  and  has  an  average  thickness,  as  determined  by  auger 
borings,  of  23  feet.  This  bed  is,  for  the  most  part,  wdiite,  but  contains 
some  cream-colored  and  light -yellow  streaks  and  varies  considerably 
in  its  content  of  quartz  and  mica.  The  kaolin  on  the  greater  part  of 
the  bed  could  be  profitably  washed.  Analysis  shows  that  even  in  the 
crude  state  it  i-^  one  of  the  purest  kaolins  found  in  the  State.  It  is 
remarkably  plastic  but  has  low  tensile  strength.  It  burns  to  a  dense 
white  body  at  Seger  cone  9  (2390°  F.),  the  temperature  usually 
attained  in  burning  white  ware.  Small  amounts  of  tins  clay  are 
being  used  for  porcelain  ware  in  the  pottery  at  Augusta.  The  follow- 
ing analysis  shows  the  purity  of  the  clay: 
Analysis  of  kaolin  from  Gibson,  Ga. 
[E.  Everhart,  analyst.] 
Moisture  at  100°  ( ' 0.  44 
Loss  on  ignition 11.  83 
Silica 47. 37 
Alumina 38. 06 
Ferric  oxide .03 
