Depositional and irradiational history and noble gas contents of orange-black droplets in the 74002/1 core from Shorty CraterIsotopic concentrations of noble gases were assessed in grain size separates of 14 soils from a 67-cm section of lunar regolith taken on the rim of Shorty Crater. The orange-black droplets in this section were probably formed from pyroclastic eruptions about 3.6 billion years ago; they give little indication of surface exposure. The isotopic concentrations suggest that cosmic ray irradiation of the core occurred in two stages and that the core stratigraphy was inverted between stages. The first irradiation stage may have taken place immediately after pyroclastic deposition of the droplets and could have lasted about 20 million years.
Document ID
19790055196
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Bogard, D. D. (NASA Johnson Space Center Houston, Tex., United States)
Hirsch, W. C. (NASA Johnson Space Center; Northrop Services, Inc. Houston, Tex., United States)