Open AccessLocal and regional lunar regolith characteristics at Reiner Gamma Formation: Optical and spectroscopic properties from Clementine and Earth‐based data
Author(s) -
Pinet Patrick C.,
Shevchenko Vladislav V.,
Chevrel Serge D.,
Daydou Yves,
Rosemberg Christine
Publication year - 2000
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999je001086
Subject(s) - regolith , impact crater , geology , lunar mare , soil water , lunar soil , albedo (alchemy) , mineralogy , astrobiology , soil science , physics , art , performance art , art history
A detailed remote sensing survey of the Reiner Gamma Formation (RGF) region by means of Earth‐based telescopic and Clementine multispectral imaging has been made in the UV‐visible‐near‐infrared domain. The spectral mixture analysis reveals the existence of three basic end‐members relevant for modeling the observed spectral variations in the RGF vicinity. These are MB (mare background), SWS (southwest swirl), and RGS (Reiner Gamma soil). The first two components exhibit spectral characteristics consistent with a prevailing contribution of mature mare soils for the surroundings (MB) and of immature mare crater‐like soils (RGS) at RGF. The third intermediate‐albedo component (SWS) has general characteristics of a mature mare soil, but with a redder continuum slope. The reported observation can be modeled by a mechanism which would remove the finest fraction in the soil (particle diameter <45 μm) at RGF and redistribute it in the vicinity with a laterally variable proportion and local accumulations such as at SWS site. According to the available set of in situ data documenting variations in the chemical composition, in the distribution of particle sizes, and in the degree of maturity with depth in the mare regolith, the characteristics depicted at RGF are those of a subsurface soil layer from a depth of the order of 0.3–0.8 m. In our view, the simplest way to account for the whole body of information available from the present work lies in the proposition that in the area of RGF the uppermost layer of the regolith has been optically and mechanically modified by a process involving the fall of fragments of a low‐density cometary nucleus previously disrupted by tidal interaction in the Earth‐Moon system. We recognize, however, that in the present state of knowledge, one cannot rule out the hypothesized existence of a zone of seismically modified terrain peripheral to the Imbrium or Orientale basins just beneath the mare surface that would be the actual source of the RGF magnetic anomaly.