HR: 09:15h
AN: P11A-06    [PDF]
TI: Mineral Maps of the Moon
AU: * Lucey, P G
EM: lucey@higp.hawaii.edu
AF: University of Hawaii, 2525 Correa Road, Honolulu, HI 96822 United States
AU: Steutel, D
EM: dsteutel@higp.hawaii.edu
AF: University of Hawaii, 2525 Correa Road, Honolulu, HI 96822 United States
AU: Gillis, J
EM: gillis@higp.hawaii.edu
AF: University of Hawaii, 2525 Correa Road, Honolulu, HI 96822 United States
AB: Determining the global distribution of minerals on the Moon has been an important goal of lunar science[1]. We analyzed a 1 km resolution four-band global mosaic of the Moon derived from the USGS Flagstaff digital image model using a Hapke-based [2] spectral analysis model. This model includes the ability to vary modal abundance, grain size, Mg-number, glass abundance and composition and degree of space weathering via inclusion of the effects of submicroscopic iron [3]. We precalculated over 2,500 different model spectra of varying abundances of the lunar minerals and space weathering parameters. For each Clementine four-band spectrum all precomputed models are compared. Models matching the data within 0.5 percent are retained. The result are relatively sparse images of the abundance of plagioclase, clinopyroxene, orthopyroxene and olivine. We then interpolated the sparse data using a nested resolution algorithm to produce a gridded data set similar to that produced for topography of Mars from MOLA data. The plagioclase image shows a distribution similar to the inverse of iron as derived from LP and Clementine data. The highlands show high values of plagioclase abundance (up to nearly 100 percent) with the mare showing low values near 40 percent. The clinopyroxene image is similar to an iron map: values are high in the mare and low in the highlands. The olivine image shows enhanced values in the western maria as previously observed by Staid and Pieters [4] and isolated exposures in other mare and the highlands. No other regional deposits of olivine are present on the Moon. Images of the ratio of olivine to the sum of mafics shows a strong variation in the highlands. The central farside shows the anorthositic material is essentially free of pyroxene. This is consistent with the observation by Pieters and Tompkins [5] that troctolites in central peaks seem concentrated in an equatorial band. Our results show this olivine enrichment includes extends to the surface. Elsewhere in the highlands, the mafic assemblage is dominated by orthopyroxene in plagioclase-rich units. References: [1] LExSWG Final Report (1995). [2] Hapke, B. (1993) Theory of Reflectance and Emittance Spectroscopy, Cambridge Univ. Press, Cambridge. [3] Lucey, P. G. (2002) GRL, 29 (10), 2001GL014655. [4] Staid, M. and C. M. Pieters (2001) JGR, 106 (E11), 27887-27900. [5] Pieters, C. M. and S. Tompkins (1999), JGR, 104 (E9), 21,935-21,949.
DE: 6250 Moon (1221)
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting