Lunar surface processes and cosmic ray histories over the past several million yearsMeasurements of the Al-26 and Mn-53 in interior portions of lunar rocks have shown that lunar surface processes which move a significant fraction of kilogram size rocks on the lunar surface occur on time scales of a few million years. These measurements, together with noble gas age dating have made it possible to define the history for nine rock samples selected from whole rock counting data because of anomalously low Al-26 relative to Na-22. Six of the rocks from the Apollo 15 and 16 missions showed evidence of movement during the past five million years. Of these six, only two are of an age consistent with their origin from the South Ray Crater Event. In addition, our measurements of Na-22 and Al-26 in Apollo 17 double drive tube 74001-74002 suggest that one to two cm of soil is missing from the top of this core tube. Even with this loss, at least two cm of gardening is indicated in the top portion of 74002.
Document ID
19790055199
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Fruchter, J. S. (Battelle Northwest Labs. Richland, WA, United States)
Rancitelli, L. A. (Battelle Northwest Labs. Richland, WA, United States)
Evans, J. C. (Battelle Northwest Labs. Richland, WA, United States)
Perkins, R. W. (Battelle Pacific Northwest Laboratories Richland, Wash., United States)