Sulfataric wall inside the crater at Kilauea, HI



S-banks site near Kilauea, HI

     We acquired the ASD visible/near-infrared (VNIR) field spectrometer and have tested it out on several rocks and soils. Preliminary samples measured include a variety of sulfate minerals, acid mine drainage materials and some other Fe- and S-bearing samples.We are in the process of developing a library with this spectrometer for comparison of spectra collected in the field. High quality reflectance spectra were measured at the NASA-supported Brown University Reflectance Experiment Lab (RELAB) of an acid mine drainage precipitate containing the minerals gypsum and ferrihydrite and a crystalline rock composed of the hydrated iron sulfate mineral rozenite that were collected at the Iron Mountain site in CA.These spectra were analyzed and compared with VNIR and mid-IR spectra of minerals and convolved to the spectral parameters of Martian Pathfinder, Pancam and mini-TES spectra. Emittance spectra and Mossbauer spectra were also measured of these samples by colleagues. Analyses of the Martian rocks and soil were preformed in comparison with these samples and it was shown that hydrated iron sulfate minerals such as the rozenite collected at Iron Mountain are consistent with many of the spectral and chemical properties of the global Martian dust observed currently at Gusev Crater and previously at the Pathfinder landing site. These results were reported at the Abscicon 2004 meeting (Bishop and Banfield, 2004) and a paper on this work has been published recently.

Recent research:

• Bishop, J.L., Dyar, M.D., Lane, M.D., Banfield, J.F., 2004, Spectral Identification of Hydrated Sulfates on Mars and Comparison with Acidic Environments on Earth, IJA, 3(4): 275-285.
• Lane, M.D., Dyar, M.D., Bishop, J.L., 2004, Spectroscopic evidence for hydrous iron sulfate in the Martian soil, GRL, vol. 31, L19702, doi:10.1029/2004GLO21231