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Clark et. al. 2003 USGS Open File Report 03-395
Spectral Library splib05a Sample Description

(For further information on spectrsocopy, see: http://speclab.cr.usgs.gov)

TITLE: Buddingtnt+Na-Mont CU93-260B DESCRIPT

DOCUMENTATION_FORMAT: Mixture

SAMPLE_ID: CU93-260B

MIXTURE_TYPE: Intimate

MIXTURE: Buddingtonite (Feldspar group)+ Na-Mont

FORMULA: (NH4)AlSi3O8*0.5H20

FORMULA_HTML: (NH4)AlSi3O8•½H20

COLLECTION_LOCALITY: Cuprite, Nevada, USA

ORIGINAL_DONOR: Gregg Swayze

COLLECTION_LATITUDE: N37deg 32.583' # degrees and decimal minutes (N or S)

COLLECTION_LONGITUDE: W117deg 11.167' # degrees and decimal minutes (W or E)

DATUM: NAD27 # coordinate datum

CURRENT_SAMPLE_LOCATION: U.S.G.S. Denver Spectroscopy Laboratory

ULTIMATE_SAMPLE_LOCATION: U.S.G.S. Denver Spectroscopy Laboratory

SAMPLE_DESCRIPTION:

Sample is from the western margin of the eastern relict hydrothermal system exposed 0.5 km east of U.S. Highway 95. Acid-sulfate alteration has altered this sample of a rhyolitic volcanic tuff converting what was once feldspar into buddingtonite, montmorillonite, and quartz. This sample was collected from a small hill that has come to be known as "Buddingtonite Bump." Buddingtonite is a NH4-feldspar.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Buddingtonite in solid-solution with K-feldspar, also quartz (analysis by Steve Sutley) Montmorillonite was not detected by XRD but may be present at levels below XRD's detection limit.

see: Felzer, B. Hauff, P., and Goetz, A.F.H., 19994, Quantitative reflectance spectroscopy of buddingtonite from the Cuprite mining district, Nevada: Journal of Geophysical Research, v.99, no. B2, p. 2887-2895.

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: NONE # XRF, EM(WDS), ICP(Trace),WChem

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

None

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

The peak in reflectance at 1.4 microns is an artifact. The band at 1.9056 microns is due to H2O. Bands at 2.0158 and 2.1114 microns are due to Buddingtonite, while the band at 2.2063 microns is due to montmorillonite. Samples similar to this have been analyzed by: Felzer, B., Hauff, P., and Goetz, A.F.H, 1994, Quantitative reflectance spectroscopy of buddingtonite from the Cuprite mining district, Nevada: Journal of Geophysical Research, v. 99, no. B2, p. 2887-2895.

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1b2_3_4_ # 1= 0.2-3, 2= 1.5-6, 3= 6-25, 4= 20-150 microns

LIB_SPECTRA_HED: where Wave Range Av_Rs_Pwr Comment
LIB_SPECTRA: splib05a r 7524 1.3-5.3µm 200 g.s.=


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