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A Near true color (stretched) B Mineral Indicator Map C
c

D
d

5 mm Low-Ca pyroxene
Olivine
Water-bearing

M6 prototype reflectance
M6 prototype reflectance
M6 prototype reflectance
E 0.4 X: 266 Y: 227 F GFe(II) electronic 0.05 Mg-OH
X: 112 Y: 108 transition matrix
D - X:242, Y:202 H2O
0.025 X:102 Y:135 0.5
0.1 0.2
C - X:214 Y:91

0.1
0.2 H2OFe-OH USGS spectral library reflectance
USGS spectral library reflectance
USGS spectral library reflectancehigh-Ca pyroxene
(AugiteNMNH120049) 0.5

Fe(II) electronic 0.8 0.4 Mg,Fe-chlorite
transition 0.4
Olivine GDS70 0.3

(Fo89) low-Ca pyroxene 0.2 serpentine (antigorite) 0.3
(Bronzite HS9.3B) 2.5 2.5
0.5 1.0 1.5 2.0 2.5 0.5 1.0 1.5 2.0 0.5 1.0 1.5 2.0
Wavelength (μm) Wavelength (μm)
Wavelength (μm)

Figure 4. Image of the Murchison meteorite acquired with UCIS. (A) Near true color composite image of a cut face of the meteorite using
hyperspectral data. (B) Mineral indicator map in which low-calcium pyroxene appears magenta, olivine is green, and water-bearing materials are
blue. Close-up of two interesting regions of the meteorite with a (C) zone of altered olivine and (D) fragment of low-calcium pyroxene. Spectra from
the USGS spectral library are shown in black and gold in (E)–(G) for comparison with meteorite spectra (Clark et al., 2007). (E) Spectra of olivine-
bearing spots with (dark green) and without (light green) spectral features indicative of hydration. (F) Spectrum of low-Ca pyroxene (shown in D),
likely from a chondrule fragment. (G) Matrix materials within the chondritic sample are clearly water-bearing but are distinctive in composition
from typical terrestrial chlorites and serpentines. The light blue spectrum is from (C).

structural H2O or fluid inclusions (Greenberger et al., 2015a). In and chemical composition. Simultaneous analysis of small-scale GSA TODAY | www.geosociety.org/gsatoday
addition, <2 mm-sized areas of datolite [CaBSiO4(OH)] formed mineralogy and texture with VSWIR microimaging spectroscopy
from boron-rich hydrothermal fluids. While datolite is apparent requires no sample preparation and can be performed on a rough
elsewhere in this outcrop and has been reported throughout the or cut surface. This approach is ideal for the survey of a collection
Hartford Basin, the areas of datolite mineralization in this sample of rare or precious samples to best target locations for follow-up
were unexpected because they are too small to be distinguished destructive or high spatial resolution analyses. It is also ideal for
visually from the abundant calcite. However, they are spectrally in situ exploration of planetary surfaces when conducting multi-
distinct in the ~133 µm/pixel VSWIR imaging data. Imaging step sample preparation procedures may be prohibitively complex.
spectroscopy correlates and scales all of these results to the hand- Analyses of the CM2 carbonaceous chondrite Murchison from
sample (full cross section of the pillow lava; Figs. 3A–3B) and to the Arizona State University meteorite collection were conducted
portions of the outcrop characterized by similar green alteration with UCIS in micro-imaging mode (~80 µm/pixel; Fig. 4)
rinds, and the same spectral features are observed at all scales. (Ehlmann et al., 2014; Van Gorp et al., 2014; Green et al., 2015).
These results are consistent with a scenario in which the pillow Olivine-rich chondrules (green areas, Fig. 4B) of varying sizes are
lavas were altered initially after emplacement at high tempera- observed throughout the sample, and UCIS data permit ready
tures, overprinted by a progressively cooling hydrothermal identification of an atypical area, no more than a few pixels in
system, and then altered after burial through diagenesis, specifi- size, with a low-calcium pyroxene-rich clast, most likely a chon-
cally albitization followed by calcite precipitation (Greenberger et drule fragment (magenta, Figs. 4D and 4F). Chondrules where
al., 2015a, and references therein). olivine is affected by aqueous alteration (dark green spectrum)
versus those unaffected (light green) can be discriminated
EXAMPLE 3: METEORITES, MAPPING OF PRECIOUS (Fig. 4E), and several Fe/Mg phyllosilicate alteration phases are
MATERIALS NON-DESTRUCTIVELY mapped in the matrix (blue areas in Fig. 4B; blue spectra in
Fig. 4G). In addition, comparisons of the near true color image
Analysis of geological samples typically requires preparation of with infrared mapping in Figures 4A–4B show that visually
thin sections or powders for determination of crystal structure

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