2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM

Paper No. 16
Presentation Time: 11:45 AM

The LHT (Lunar Highlands Type) Regolith Simulant Series

STOESER, Douglas1, WILSON, Steve2, WEINSTEIN, Michael3, RICKMAN, Douglas L.4, LOWERS, Heather2, MEEKER, Gregory2, SCHRADER, Christian M.5, MCLEMORE, Carole4 and FIKES, John4, (1)Central Mineral and Environmental Resources Science Center, USGS, Mail Stop 973 Box 25046 DFC, Denver, CO 80225, (2)U.S. Geological Survey, Denver, CO 80225, (3)Zybek Avanced Products, Inc, Boulder, CO 80301, (4)NASA, Huntsville, AL 35801, (5)Marshall Space Flight Center, NSSTC, 320 Sparkman Drive, Huntsville, AL 35805, dstoeser@usgs.gov

Three NU-LHT (NASA/USGS-Lunar Highlands Type) regolith simulants have been produced to date: NU-LHT-1M, -1D, and -2M. A fourth simulant is currently in production: NU-LHT-3C. The “M” (medium) designation indicates a simulant with a grain size of <1 mm, “D” (dust) a simulant with a grain size of <36 µm, and “C” (coarse) a simulant with a 10 cm maximum particle size. The composition of these simulants is based on a NASA average Apollo 16 regolith chemical composition. However, the mixing model used to create our simulants is based on cationic normative mineral proportions derived from the target chemical composition to approximate lunar modal mineralogy rather than chemical composition per se. Accordingly, the amount of plagioclase, pyroxenes, olivine, and trace minerals in the simulant crystalline fraction approximates that of the lunar regolith. We also added synthetic agglutinate in amounts approximate for low-medium regolith maturity. A pure glass fraction was also added to simulate other types of lunar glasses present in the regolith. In addition, the 3C simulant will include synthetic impact melt breccia clasts for the >1 cm particles. The bulk raw materials used to create these simulants include clinopyroxene-norite, anorthosite, hartzburgite and noritic mill waste from the Stillwater Mine, Nye, MT, and olivine from the Twin Sisters dunite, WA. Added trace minerals include beach sand ilmenite, chromite, synthetic β-tricalcium phosphate (whitlockite), gem grade fluor-apatite, and pyrite. The agglutinate, glasses, and synthetic breccia were designed and prepared at an industrial plasma melting facility in Boulder, CO, using Stillwater mill waste feedstock for the melt. These simulants do not include nanophase-Fe0. The M and C simulant grain size distribution (down to 0.4 µm) approximates that of the Apollo 16 regolith and the regolith in general.