The Reiner Gamma Formation - Composition and origin as derived from remote sensing observations

In order to investigate the composition and origin of Reiner Gamma, near-infrared spectra and vidicon images were obtained and interpreted. The 0.40/0.56 micron ratio image shows that the high albedo portion of Reiner Gamma is surrounded by a 'red halo' and the 0.95/0.56 micron image indicates that Reiner Gamma exhibits a strong pyroxene absorption band. Analysis of the near-infrared spectra of various portions of the formation indicated the presence of major amounts of fresh mare basalt. Spectral mixing models demonstrate that the Reiner Gamma spectra can be reproduced by mixing major amounts of local fresh mare material (Reiner K crater) with small amounts of fresh highlands material (Oelbers A crater). No evidence was found for the presence of 'exotic' components (i.e., magnetite, free iron, cometary material). Together with photogeologic considerations, these results suggest that Reiner Gamma is quite young and is composed of a mixture of fresh highland materials with much larger quantities of local mare basalt.