USGS Certificate of Analysis Diabase, W-2 (Geochemical Reference Standards)

Material was collected in 1976 from the Bull Run quarry near Centreville, Virginia. This is the same collection site as USGS reference mateirals W-1 (Fairbairn, 1950). The diabase consists of augite and plagioclase with smaller amounts of quartz, potassium feldspar, biotite and opaque minerals.

Recommended Concentrations

Values listed are derived using at least two independent techniques from at least two independent laboratories. Statistical treatment of the data uses the procedures outlined in previous USGS publications (Flanagan and Gottfried, 1980). Supplemental information is derived from international data compilations (Gladney and Roelandts, 1988, Govindaraju, 1994,).

Information values

Values are presented when only a single method of analysis was used or results from independent laboratories are not in statistical agreement.

Recommended Values

Oxide	Wt %	±	Oxide	Wt %	±
Al₂O₃	15.45	0.16	MgO	6.37	0.058
CaO	10.86	0.078	MnO	0.167	0.004
Fe₂O₃	1.53	0.87	Na₂O	2.20	0.037
FeO	8.34	0.093	P₂O₅	0.14	0.12
Fe₂O₃T	10.83	0.21	SiO₂	52.68	0.29
K₂O	0.626	0.012	TiO₂	1.06	0.01

Element	µg/g	±	Element	µg/g	±	Element	µg/g	±
Ba	170	11	Hf	2.6	0.18	Sr	190	3
Ce	23	1.5	La	10	0.59	Th	2.4	0.1
Co	43	2.1	Li	9.6	0.54	V	260	12
Cr	92	4.4	Nd	13	1	Y	23	1.6
Cu	110	4.9	Ni	70	2.5	Yb	2.1	0.2
Dy	3.6	0.8	Rb	21	1.1	Zn	80	2
Eu	1.0	0.06	Sc	36	1.1	Zr	100	2
Ga	17	0.89	Sm	3.3	0.13

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Information Values

Element	µg/g	Element	µg/g	Element	µg/g
As	1.2	F	205	Sb	0.79
B	12	Ho	0.76	Ta	0.5
Be	1.3	Lu	0.33	Tb	0.63
Cl	190	Nb	7.9	Tm	0.38
Cs	0.99	Pb	9.3	U	0.53
Er	2.5	S_tot	79

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Certificate Information

Denver, Colorado
revised March 1995

David B. Smith
Central Region Mineral Resources Team (formerly Branch of Geochemistry)

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Bibliography

Flanagan, F.J., and Gottfried, D., 1980, USGS rock standards III; Manganese-nodule reference samples USGS NOD-A-1 and USGS-NOD-P-1: U.S. Geological Survey Professional Paper 1155, 39 p.

Flanagan, F.J., 1984, Three USGS Mafic Rock Reference Samples, W-2, DNC-1, and BIR-1: U.S. Geological Survey Bulletin 1623, p. 54.

Gladney, E.S., and Roelandts, I., 1988, 1987 Compilation of Elemental Concentration Data for USGS BIR-1, DNC-1, and W-2: Geostandards Newsletter, 12:63-118.

Govindaraju, K., 1994, 1994 Compilation of Working Values and Descriptions for 383 Geostandards: Geostandards Newsletter, 18:1-158.

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Glossary

Symbol	Definition
Fe₂O₃T	Total iron expressed as Fe₂O₃
C_tot	Total carbon concentration
S_tot	Total sulfur concentration
Wt %	Percent of total element concentration
µg/g	Total element concentration expressed as micrograms of element per gram of solid sample
±	One standard deviation

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Notes

Unless otherwise indicated total element concentrations are reported for material on an as-received basis, i.e., no drying.

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Order and Pricing Information

Placing an Order

USGS reference materials (RMs) may be obtained directly from Dr. Stephen A. Wilson. The price for each RM is listed in U.S. dollars and are subject to change. For domestic orders, this cost includes all shipping and handling charges using normal mail delivery by the U.S. Postal Service. For foreign orders, delivery charges will be added to the final bill. Urgent requests for RMs should be initiated by Fax or e-mail. If required, expedited delivery is available with any additional shipping charges added to the final bill.

To order a USGS Reference Material, please contact Dr. Stephen Wilson or use the downloadable order form: Word format (48 KB) or PDF format (28 KB).

Dr. Stephen A. Wilson
U.S. Geological Survey
Box 25046, MS 964D
Denver, CO 80225
Tel: 303-236-2454
FAX: 303-236-3200 or 303-236-1425
e-mail: (swilson@usgs.gov)

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User Agreements

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Please download the appropriate version of the agreement and follow the instructions on the form when placing your order.

User agreement for domestic users: Word format, 48 KB and PDF format, 124 KB.
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