Table 2. Mineralogy of the sodium-carbonate-dispersible fine 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							y
LA-Foley-Btg2	6					1
TX-Booneville-Ap	6					1
KY-Maury-Ap	6		1		1	3							y
KY-Maury-Bt	6	1			1	2							y
KY-Memphis-Ap	5				1	5							y
KY-Memphis-Bt2	5				2	4
TN-Memphis-Ap	3				6	3							y
TN-Memphis-Bt	5				5	2							y
FL-Astatula-C			4		1	3	5	1	1
NC-Wayah-A2			6		2	2	2
NC-Wayah-Bw2	2		1		3	2	5
OK-Kirkland-Bt	6				3	1	1
PR-Nipe-			1			5	3	3	1
FL-Pomona-Bh			3		1	6			1
PR-Consumo-Ap			1		1	6	1	1
PR-Consumo-B			1			6	1	1
PR-Humatas-Ap			1			6		1
PR-Humatas-B			1		1	6		1
GA-Cecil-Ap			1			6	3	1
GA-Cecil-Bt			1			6	3	1
NC-Hayesville-Ap			2		2	4	4	1	1
NC-Hayesville-Bt2			2			4	6	1	1
NC-Hayesville-C2			1		2	3	5	1	1
AL-Decatur-Ap			2		1	6	2
AL-Decatur-Bt			1		1	6	2
GA-Orangeburg-Ap			1			6	3	1
GA-Dyke-Ap			3		1	5	4	1
FL-Millhopper-Btg			1			6	1
NJ-Marlton-A1					6	1
NJ-Marlton-Bt2					6	1
LA-Sharkey-Ap	6					1
OK-Heiden-C2	6				2	3		1

* "y" designates small amounts of regularly mixed layered vermiculite/illite.
** "y" designates a significant extent of random mixed layering of smectite and kaolinite.