Table 1. Mineralogy of the water-dispersible clay fraction. Numbers in columns designate relative percent ranges as estimated from calibrated XRD peak intensities: <10% = 1;  10-20% = 2;  20-30% = 3;  30-40% = 4;  40-50% = 5;  >50% = 6.
 
Sample
Mineral
Smectite
Vermiculite
Hydroxy-
interlayered
Minerals
Chlorite
Illite
Kaolinite
Gibbsite
Goethite
Quartz
Feldspar
Calcite
V/I*
S/K**
LA-Foley-Ap
6
1
1
2
2
LA-Foley-Btg2
6
1
1
1
TX-Booneville-Ap
6
1
1
KY-Maury-Ap
1
2
1
5
2
2
KY-Maury-Bt
1
3
5
3
2
KY-Memphis-Ap
2
2
1
5
3
1
KY-Memphis-Bt2
2
1
1
5
3
1
TN-Memphis-Ap
2
1
5
2
2
TN-Memphis-Bt
2
1
5
2
1
FL-Astatula-C
6
2
3
1
1
NC-Wayah-A2
2
4
1
3
2
y
NC-Wayah-Bw2
1
2
2
6
2
y
OK-Kirkland-Bt
6
4
1
1
PR-Nipe-
1
3
4
3
1
FL-Pomona-Bh
6
3
3
PR-Consumo-Ap
1
6
1
PR-Consumo-B
6
1
PR-Humatas-Ap
1
6
1
1
PR-Humatas-B
1
1
6
1
1
GA-Cecil-Ap
2
1
6
2
1
1
GA-Cecil-Bt
1
1
6
2
1
1
NC-Hayesville-Ap
2
1
3
6
1
1
1
NC-Hayesville-Bt2
1
1
3
6
1
1
NC-Hayesville-C2
1
1
4
6
1
1
y
AL-Decatur-Ap
1
2
6
2
1
2
1
AL-Decatur-Bt
1
2
6
2
1
1
1
GA-Orangeburg-Ap
4
4
3
1
1
GA-Dyke-Ap
2
1
3
5
1
1
FL-Millhopper-Btg
1
6
1
NJ-Marlton-A1
6
1
1
NJ-Marlton-Bt2
6
1
1
LA-Sharkey-Ap
6
1
2
1
1
OK-Heiden-C2
3
4
3
1
1
1
* "y" designates small amounts of regularly mixed layered vermiculite/illite.
** "y" designates a significant extent of random mixed layering of smectite and kaolinite.