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(For further information on spectroscopy, see:
http://speclab.cr.usgs.gov)
TITLE: Hematitic Alt. Tuff CU91-223 DESCRIPT
DOCUMENTATION_FORMAT: MIXTURE
SAMPLE_ID: CU91-223
MIXTURE_TYPE: Intimate
MIXTURE: Hematite + other mineral phases
FORMULA: alpha-Fe2O3
FORMULA_HTML: alpha-Fe2O3
COLLECTION_LOCALITY: Eastern Alteration Center, Cuprite, Nevada, USA
ORIGINAL_DONOR: Gregg Swayze
COLLECTION_LATITUDE: N37 33.083' # degrees and decimal minutes (N or S)
COLLECTION_LONGITUDE: W117 10.68' # 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 is of a hematitically altered rhyolite tuff from the relict eastern hydrothermal center at Cuprite, NV. Alteration occurred about 7.6 Ma. Sample was collected from the northwest part of the eastern center.
END_SAMPLE_DESCRIPTION.
XRD_ANALYSIS:
Poorly crystallized hematite, kaolinite, quartz, calcite, and tridymite (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:
Spectrum has absorptions characteristic of hematite with a broad Fe absorption at 0.884 microns. Kaolinite doublets are present near 1.4 and 2.2 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history of the Cuprite Mining District, southwestern Nevada: an integrated geological and geophysical approach: unpublished Ph.D. Dissertation, University of Colorado at Boulder, 399p.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: 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 8318 | 0.2-3.0µm | 200 | g.s.= |
| LIB_SPECTRA: | splib06a r 25396 | g.s.= |