Thorium concentrations in the lunar surface. V - Deconvolution of the central highlands regionThe distribution of thorium in the lunar central highlands measured from orbit by the Apollo 16 gamma-ray spectrometer is subjected to a deconvolution analysis to yield improved spatial resolution and contrast. Use of two overlapping data fields for complete coverage also provides a demonstration of the technique's ability to model concentrations several degrees beyond the data track. Deconvolution reveals an association between Th concentration and the Kant Plateau, Descartes Mountain and Cayley plains surface formations. The Kant Plateau and Descartes Mountains model with Th less than 1 part per million, which is typical of farside highlands but is infrequently seen over any other nearside highland portions of the Apollo 15 and 16 ground tracks. It is noted that, if the Cayley plains are the result of basin-forming impact ejecta, the distribution of Th concentration with longitude supports an origin from the Imbrium basin rather than the Nectaris or Orientale basins. Nectaris basin materials are found to have a Th concentration similar to that of the Descartes Mountains, evidence that the latter may have been emplaced as Nectaris basin impact deposits.
Document ID
19820048188
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Metzger, A. E. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Etchegaray-Ramirez, M. I. (Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA, United States)
Haines, E. L. (California Institute of Technology, Jet Propulsion Laboratory, Pasadena CA, United States)