Fossil track and thermoluminescence studies of Luna 20 material
Abstract
Track densities in 85 feldspar crystals from L-2009 range from 2.5 × 10 6/ cm2 to > 10 9/cm 2. This track distribution represents an intermediate case between what have been previously defined as lightly and heavily irradiated soils and suggests that the Luna 20 sample consists of a mixture of a mature, heavily irradiated component with another, lightly irradiated component. Using a two component mixing model, the age of the lightly irradiated component is ~270 × 10 6 yr. It is possible, but by no means certain, that this is associated with the formation of the crater Apollonius C. At ~200°C the ratio of natural TL to that induced by a standard irradiation is similar to that in Apollo 12 and 14 cores below ~7 cm. This confirms that most of the Luna 20 sample represents sub-surface material.
- Publication:
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Geochimica et Cosmochimica Acta
- Pub Date:
- April 1973
- DOI:
- 10.1016/0016-7037(73)90179-8
- Bibcode:
- 1973GeCoA..37..825C