Trace Element Concentration and Speciation in Selected Mining-Contaminated Soils and Water in Willow Creek Floodplain, Colorado

Table 9

Sequential extraction as percent of total extractable trace elements (TE) in study soils.

Soil			Sequential fractionations^a					Recovery^b
	Depth	WS	EX	SS/CAR	OX	OM/S	RES
	(cm)	% of total						(%)
Gravelbar	0–73	1	3	42	45	10	11	113
Cottonwood	0–90	1	21	40	36	9	12	119
Spruce	0–10	1	5	47	41	11	21	126
	10–40	1	3	41	68	9	19	140
Railroad	0–61	2	9	16	47	14	24	111
	61–120	1	11	23	48	6	25	113
Western Channel	0–40	1	4	41	42	14	10	112
Salty	0–20	16	16	43	28	5	7	115
North	0–40	1	4	37	47	14	10	113
South	0–40	4	10	31	38	10	15	108
Denuded Mound	0–40	8	22	42	15	9	7	104
Sedge Mound	0–40	2	6	28	54	12	22	124

^aSequential fractionations: WS, water soluble; EX, exchangeable; SS/CAR, specifically sorbed/carbonate bound;
OX, oxide–bound; OM/S, organic /sulfide–bound; RES, residual.
^bRecovery = (SUMSEQ/SUMTE) × 100.