Solar and cosmogenic nitrogen in the Apollo 17 deep drill coreIt is established that the greatest distinction in origin of the soils in the Apollo 17 drill core is between the surface layer, down to 25 cm, and the remainder. The surface layer was not derived by the reworking of underlying material, but was deposited from elsewhere. The soils in the core below 25 cm have had similar surface histories, with first exposure to the solar wind 1.0-1.5 million years ago and accumulation of solar wind continuously over hundreds of millions of years thereafter. The soil with the least, and most ancient, surface exposure is 25-60 cm deep, while that with the greatest and most recent exposure, other than the present surface layer, lies at a depth of 110-170 cm. A major stratigraphic sequence disturbance has therefore deposited the soils in their present positions.
Document ID
19820038796
Acquisition Source
Legacy CDMS
Document Type
Conference Proceedings
Authors
Thiemens, M. H. (Chicago Univ. Chicago, IL, United States)
Clayton, R. N. (Chicago, University Chicago, IL, United States)