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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: White_Crust LV30 (Epsomite?) DESCRIPT

DOCUMENTATION_FORMAT: Mixture

SAMPLE_ID: LV30

MIXTURE_TYPE: Intimate

MIXTURE: Epsomite + possible other salts

FORMULA: MgSO4.7H2O

FORMULA_HTML: MgSO4.7H2O

COLLECTION_LOCALITY: Arkansaa river Site 3 km south of Leadville, Colorado, USA

ORIGINAL_DONOR: Gregg Swayze

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

CURRENT_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory, Denver, Colorado

ULTIMATE_SAMPLE_LOCATION: USGS Denver Spectroscopy Laboratory, Denver, Colorado

SAMPLE_DESCRIPTION:

White Crust (Epsomite?) Arkansas River Site Leadville LV30. This crust formed about saturated fluvial mine tailings rich in pyrite. Apparently water saturated with salts wicked up through permeable fine-grained sand and formed the white salt crust at the surface when the liquid evaporated. It may be possible that the epsomite is mixed with other salts and trace metals may substitute for Mg (e.g. As etc). This type of salt deposit is typical of acid mine drainage and when dissolved by rain or other precipitation causes a quick release of metals into streams.

END_SAMPLE_DESCRIPTION.

XRD_ANALYSIS:

none

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 spectral features closely resemble those of epsomite in standard GDS149. The presence of a band at 1.6237 and 2.207 may be diagnostic of epsomite and perhaps other salts.

END_SPECTROSCOPIC_DISCUSSION.

SPECTRAL_PURITY: 1c2_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 9029 0.2-3.0µm 200 g.s.=


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