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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: Gyp+jar+ill BRCM1 Marysvale DESCRIPT

DOCUMENTATION_FORMAT: MIXTURE

SAMPLE_ID: BRCM1

MIXTURE_TYPE: Intimate

MIXTURE: Gypsum, Jarosite, Illite.

FORMULA: CaSO4*2H2O and Na,K(Fe+3)3(SO4)2(OH)6 and (K,H30)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2,H20]

FORMULA_HTML: CaSO4*2H2O and Na,K(Fe+3)3(SO4)2(OH)6 and (K,H3O)(Al,Mg,Fe)2(Si,Al)4O10[(OH)2H2O

COLLECTION_LOCALITY: Big Rock Candy Mountain, Marysvale, Utah USA

ORIGINAL_DONOR: Barnaby Rockwell

COLLECTION_LATITUDE: N38deg 30.7053' # degrees and decimal minutes (N or S) COLLECTION_LONGITUDE: W112deg 15.7402' # 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:

ASD lab spectrum of sample BRCM1 from Big Rock Candy Mountain, Marysvale, Utah. XRD: Natural intimate mix of quartz, albite, gypsum, natrojarosite, pyrite, illite/muscovite. Proximal propylitic alteration from feeder zone.

Weathered andesitic lava flows from pyritic, propylitically altered feeder zone of hydrothermal system formed at ~21 Ma (Miocene). Fine-grained, yellowish jarositic coatings on light grey, thoroughly altered rock.

See: Rockwell, B.W.,2002, Descriptions, spectral plots, and digital reflectance spectra of samples applied to spectral analysis of imaging spectroscopy data: Utah (East Tintic Mountains, Oquirrh Mountains, Wasatch Mountains, and Tushar Mountains), Nevada (Goldfield Hills), and New Mexico (Jemez Mountains), USA, 1999-2002: U.S. Geological Survey Open-File Report 02-407, electionic webpages. (http://pubs.usgs.gov/of/2002/ofr-02-407)

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

Albite (major), quartz (minor), gypsum (minor), natrojarosite (minor), illite (minor), muscovite (minor), pyrite (trace), dolomite (trace).

See: Rockwell, B.W.,2002, Descriptions, spectral plots, and digital reflectance spectra of samples applied to spectral analysis of imaging spectroscopy data: Utah (East Tintic Mountains, Oquirrh Mountains, Wasatch Mountains, and Tushar Mountains), Nevada (Goldfield Hills), and New Mexico (Jemez Mountains), USA, 1999-2002: U.S. Geological Survey Open-File Report 02-407, electionic webpages. (http://pubs.usgs.gov/of/2002/ofr-02-407)

END_XRD_ANALYSIS.

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

COMPOSITION_TRACE: None

COMPOSITION_DISCUSSION:

None

END_COMPOSITION_DISCUSSION.

MICROSCOPIC_EXAMINATION:

Scanning Electron Microscope (SEM) images found crystals of natrojarosite ranging in size from 2-5 microns in diameter, large crystals of gypsum of 10 microns and larger, and amorphous coatings of iron oxides and hydroxides around grains of other minerals.

END_MICROSCOPIC_EXAMINATION.

SPECTROSCOPIC_DISCUSSION:

Spectrum has many spectral features. The electronic region (.35-1.35 micrions) is dominated by the spectral features of jarosite while the 1.4 and 2 micron regions have bands attributable to all jarosite, gypsum, and illite.

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 8203 0.2-3.0µm 200 g.s.=


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