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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: Basalt_weathered BR93-43 DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: BR93-43

MIXTURE_TYPE: Intimate

MIXTURE: Anorthite (Tectosilicate - Plagioclase, Ca end member, Feldspar group), Augite (Inosilicate - Pyroxene group), Calcite (Carbonate - Calcite group), Hematite (Oxide - Hematite group)

FORMULA: CaAl2Si2O8, (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6, CaCO3, and Fe2O3

FORMULA_HTML: CaAl2Si2O8, (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)2O6, CaCO3, and Fe2O3

COLLECTION_LOCALITY: Newberry Mtns, Southeast of Barstow, CA, USA

COLLECTION_LATITUDE: Not Available # degrees and decimal minutes (N or S)

COLLECTION_LONGITUDE: Not Available # degrees and decimal minutes (W or E)

DATUM: Not Available # coordinate datum

ORIGINAL_DONOR: Eric Livo

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

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

SAMPLE_DESCRIPTION:

Slightly to moderately weathered basalt with a slight vesicular texture; some filled with calcite. Rock has a fine grained ground mass with a few augite phenocrysts. Its purple color is due to hematite.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Major: Calcite
Minor: Anorthite, Augite, Hematite
Trace: Montmorillonite
Note: Calcite is a minor component of the rock as a whole

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

No additional compositional details available.

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

END_MICROSCOPIC_EXAMINATION.

IMAGE_OF_SAMPLE: Not Available

SPECTROSCOPIC_DISCUSSION:

Strong Fe+2 (Augite) absorption feature at one micron with a lesser signature of Fe+3 (Hematite) in the visible to near-IR. Minor Calcite and Montmorillonite absorption features occur at 2.3 and 2.2 microns.

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 7492 0.2-3.0µm 200 g.s.=


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