FeO and TiO2 concentrations in the South Pole-Aitken basin: Implications for mantle composition and basin formation

Abstract

We use newly developed spectroscopic methods for determining FeO and TiO2 abundances to study the huge (2500 km diameter) South Pole-Aitken basin. The floor of this basin shows iron and titanium values which are weakly correlated and largely range from 7 to 14 wt% FeO and from 0.5 to 1.5 wt% TiO2. This composition is consistent with an approximate 1:1 mixture of lower crustal material like that found elsewhere on the Moon and mantle rock containing 10-16 wt% FeO and < 0.1 wt% TiO2. Although mantle rock appears to compose about 50% of the floor deposits, models of the formation of large impact basins predict that virtually all the floor materials ought to be derived from the mantle. Copyright 1998 by the American Geophysical Union.