Global Lunar Titanium Classification

Abstract

Multispectral data obtained by the Galileo spacecraft in Decemger 1992 have been corrected for radiometric, geometricand photometric effects. The spectral reflectance has been caculated and a simple cylindrical map projection has been performed. Using the correlation of UV-VIS ratio (violet/green) and the titanium content of surface material (Charette et al., 1974) it is possible to determine the titanium concentration of mature lunar soils. According to our classifiaction scheme we found 4 classes of distinctive titanium contents (low &#61 <2 wt%, medium &#61 2-4 wt%, medium-high &#61 3-7 wt% and high &#61> 6 wt%) on the lunar surface. Our results confirm the so far identified titanium concentrations in the eastern maria but we also detected high titanium content in the western Oceanus Procellarum and in the area of a numver of dark mantle deposits. We found medium titanium concentrations in Mare Marginis, Mare Smythii and Mare Nectaris, and a low titanium content in Mare Frigoris. Western regions of Mare Humboldtianum seem to be relatively poor in titanium. The parts of southern Mare Crisium are richer in titanium than are the northern areas. The central protion of Mare Fecunditatisis titanium rich, with a gradual decline to the southeastern border and the passage into Mare Tranquillitatis. Basalts that flooded Archimedes and Plato are generally low in titanium content.