Table 2.

ICP-MS analysis of magnetic separates.

Element	Unit	Tucson roof silt magnetics		Curry Draw streambed magnetics		Clovis surface F2/F1 Profile B3 magnetics		Approximately 1 cm below Clovis Surface—F1 sand surface
		1AZ07	2σ	16MS07	2σ	26MS07	26	3-5MS07	2σ
Fe	wt %	45.3	1.2	9.6	0.4	27.1	0.8	5.7	0.2
Ti	wt %	0.8	0.1	6.9	0.2	2.2	0.1	5.1	0.5
W	ppm (μg/g)	202	11	794	9	496	64	1132	85
Ni	ppm (μg/g)	6	5	53	25	67	32	28	20
La	ppm (μg/g)	19	15	124	60	38	28	347	219
Nd	ppm (μg/g)	20	3	95	5	27	2	225	16
Sm	ppm (μg/g)	3.6	1.7	18	2	4.8	1.6	35	3
Eu	ppm (μg/g)	BDL*		0.2†	3.5	BDL		1.2†	4.3
Gd	ppm (μg/g)	5.7†	7.2	22	11	5.0†	8.1	34	26
Tb	ppm (μg/g)	0.6†	1.4	2.7	1.5	0.4†	1.4	4.6	1.6
Dy	ppm (μg/g)	4.4†	4.9	16	4	3.3†	3.7	26	4
Ho	ppm (μg/g)	BDL		2.1†	3.5	BDL		3.8†	3.8
Er	ppm (μg/g)	1.2†	4.5	8.5	7.7	0.1†	4.2	16	6
Tm	ppm (μg/g)	0.2†	0.9	1.9	1.3	0.1†	0.8	2.6	1.0
Yb	ppm (μg/g)	BDL		8.5†	25.9	BDL		21†	54.0
Lu	ppm (μg/g)	BDL		13.4†	16.6	6.6†	10.5	5.4†	6.3
Hf	ppm (μg/g)	29	1	192	8	155	12	124	3
Ta	ppm (μg/g)	83	4	709	35	73	2	710	30
U	ppm (μg/g)	6.3	0.6	9.1	0.8	3.1	0.6	7.7	1.9
Ir	ppb (ng/g)	0.9†	34	72	30	64	22	31	29

^*BDL: sample signal below blank.

^†Sample signal overlaps with blank at 2σ level.