Nested-crater model of lunar ringed basinsWe propose a model for the origin of impact-basin rings whereby the main topographic rim of a basin approximates the limit of excavation and inner rings approximate the rims of craters formed inside the transient crater by some perturbation in the cratering process. The cause of this complexity in transient cavities may be the presence of discontinuities in the target material. The second inward ring may have formed at the seismic discontinuity about 20 km deep in the lunar crust, and the third, innermost ring of a few large basins at the crust-mantle interface about 60 km deep. Slumping increased the original diameters of many rings and split some initially coherent rings into subsidiary or partial rings. Deformation outside the transient crater produced external arcs. This model differs from prevalent hypotheses of ring formation whereby an inner ring approximates the transient crater rim and major faulting of the flank produced the outer ring structures.
Document ID
19780060143
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Wilhelms, D. E. (Geological Survey Menlo Park, CA, United States)
Hodges, C. A. (Geological Survey Menlo Park, CA, United States)
Pike, R. J. (U.S. Geological Survey Menlo Park, Calif., United States)
Date Acquired
August 9, 2013
Publication Date
January 1, 1977
Subject Category
Lunar And Planetary Exploration
Meeting Information
Meeting: Symposium on Planetary Cratering Mechanics