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Erratum
In the December 2015 GSA Today science article (v. 25, no. 12, p. 4–10), “Imaging spectroscopy of geological samples and outcrops: Novel
insights from microns to meters,” by Rebecca N. Greenberger et al., the scale bars for Figure 2 were inadvertently removed. The corrected
figure is below. GSA Today regrets this error.

A Photograph B Spectral cube with mineral C Representative spectra
indicators c) Calcite
1
Serpentine H2O 2
Tetr. Fe3+
Calcite C-O

1
GSA TODAY | JANUARY 2016 Calcite + 3
eacRheflweacvtealnecnegtaht serpentine
Reflectance (offset for clarity)
4 Serpentine

Fe2+ 4

2 Serpentine
with tetr. Fe3+

Tetrahedral OH Mg-OH Tetr.
Fe3+
Fe3+

1 cm 1 cm 3 0.5 1.0 1.5 2.0 2.5 0.5
Wavelength (μm)

Figure 2. Hyperspectral image of a serpentinite sample with red and green coatings (Nor4-14, described in Greenberger et al., 2015b) from Norbestos, Quebec,
Canada. (A) Photograph of the full rock. (B) Image showing spectral parameters that map calcite (red), serpentine (green), and a feature at 0.45 µm (BD450; blue)
due to tetrahedral Fe3+ within serpentine. The third dimension shows the reflectance as a function of wavelength for each pixel within the image, with black and
purple being low and red high. (C) Plot with representative spectra of different units within the hyperspectral image. Colors correspond to colors in the spectral
parameter image with locations numbered. Close-up views of the 0.45 µm feature are shown on the right. These images were acquired with Headwall Photonics
Inc. High Efficiency Hyperspec® visible–near-infrared E-series (0.4–1.0 µm, 7 nm spectral resolution, 0.382 mrad instantaneous field of view) and High Efficiency
Hyperspec® shortwave infrared X-series pushbroom systems (1.0–2.5 µm, 12 nm spectral resolution, 1.2 mrad instantaneous field of view) imaging spectrometers

50 (see GSA Supplemental Data Repository item no. 2015342 for more information).