Characterization of alteration products in tephra from Haleakala, Maui : A visible-infrared spectroscopy, Mössbauer spectroscopy, XRD, EMPA and TEM study
Bishop, Janice L (NASA-Ames Research Center)
Schiffman, Peter (Department of Geology. University of California)
Murad, Enver (Bayerisches Landesamt für Umwelt)
Dyar, M. Darby (Mount Holyoke College)
Drief, Ahmed (The Clorox Company)
Lane, Melissa D. (Planetary Science Institute)

Data:	2007
Resum:	Altered basaltic tephra from Haleakala, Maui, are characterized using multiple techniques in order to identify the minerals formed under a variety of conditions and to understand the soil formation processes here. We collected samples that are representative of typical bulk weathered material in the crater, as well as solfataric alteration in a hydrothermal environment. For this study X-ray diffraction, electron probe microanalysis, scanning electron microscopy and transmission electron microscopy are coupled with spectroscopic techniques including Mössbauer, visible-infrared reflectance, transmission infrared, and thermal infrared emission spectroscopies to analyze these samples. The unaltered tephra are composed of feldspar, glass, pyroxene and olivine. Observed alteration products include Fe oxides, phyllosilicates and sulfates, as well as SAED amorphous Al-Si-bearing material. These samples are potential analogs for altered volcanic material on Mars as the pedogenic influences and contact with plants and animals are minimal. Results from this study may help to determine spectral signatures of these samples that could be used for identification on Mars of the minerals observed here.
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	Altered Tephra ; Alunite ; EMPA ; Infrared Spectroscopy ; Jarosite ; Mars ; Mössbauer ; SEM ; Smectite ; Solfataric Alteration ; XRD
Publicat a:	Clays and Clay Minerals, Vol. 55, Núm. 1 (2007) , p. 1-17, ISSN 1552-8367

DOI: 10.1346/CCMN.2007.0550101

17 p, 2.9 MB  Accés restringit a la UAB

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