Geomorphology of crater and basin deposits - Emplacement of the Fra Mauro formationCharacteristics of continuous deposits near lunar craters larger than about 1 km wide are considered, and it is concluded that (1) concentric dunes, radial ridges, and braided lineations result from deposition of the collision products of ejecta from adjacent pairs of similarly oriented secondary-crater chains and are, therefore, concentrations of secondary-crater ejecta; (2) intracrater ridges are produced within preexisting craters surrounding a fresh primary crater by ricocheting and focusing of secondary-crater ejecta from the preexisting craters' walls; and (3) secondary cratering has produced many of the structures of the continuous deposits of relatively small lunar craters and is the dominant process for emplacement of most of the radial facies of the continuous deposits of large lunar craters and basins. The percentages of Imbrium ejecta in deposits and the nature of Imbrium sculpturing are investigated.
Document ID
19780062837
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Morrison, R. H. (LFE Corp. Richmond, Calif., United States)
Oberbeck, V. R. (NASA Ames Research Center Moffett Field, Calif., United States)