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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: Pyroxene Basalt CU01-20A DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: CU01-20A

MIXTURE_TYPE: Intimate

MIXTURE: Pyroxene + other mineral phases

FORMULA: Not Available

FORMULA_HTML: Not Available

COLLECTION_LOCALITY: 6 km south of Western Center, Cuprite, Nevada, USA

ORIGINAL_DONOR: Gregg Swayze

COLLECTION_LATITUDE: N37 29.12' # degrees and decimal minutes (N or S)

COLLECTION_LONGITUDE: W117 14.48' # degrees and decimal minutes (W or E) P> 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:

This sample was collected from the instrusive basalt plug 6 km south of the western alteration center within the Cuprite Hills. The sample spectrum was of a slightly weathered surface. Most other surfaces in the intrusive body are heavily coated with desert varnish and hence have much weaker pyroxene absorptions.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Augite (major), diopside (major), anorthite (major), forsterite (trace), quartz (trace), analcime (trace).

END_XRD_ANALYSIS.

COMPOSITIONAL_ANALYSIS_TYPE: XRF # XRF, EM(WDS), ICP(Trace), WChem

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

None

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

The spectrum has characteristic absorptions from pyroxene at 1.0391 microns with very weak absorptions from hydrated phases (clays?) at 2.2057 and 2.3113 microns.

See: Swayze, G.A., 1997, The hydrothermal and structural history of the Cuprite Mining District, southwestern Nevada: an integrated geological and geophysical approach: unpublished Ph.D. Dissertation, University of Colorado at Boulder, 399p.

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1a2_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 8966 0.2-3.0µm 200 g.s.=


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