Radiocarbon Beyond this World

Abstract

ABSTRACT. In this paper, we review the production of radiocarbon and other radionuclides in extraterrestrial materials. This radioactivity can be produced by the effects of solar and galactic cosmic rays on solid material in space. In addition, direct implantation at the lunar surface of 14 C and other radionuclides can occur. The level of 14 C and other radionuclides in a meteorite can be used to determine its residence time on the Earth's surface, or "terrestrial age". 14 C provides the best tool for estimating terrestrial ages of meteorites collected in desert environments. Age control allows us to understand the time constraints on processes by which meteorites are weathered, as well as mean storage times. Third, we discuss the use of the difference in 14 C/ 12 C ratio of organic material and carbonates produced on other planetary objects and terrestrial material. These differences can be used to assess the importance of distinguishing primary material formed on the parent body from secondary alteration of meteoritic material after it lands on the earth.

Noble gases in ten Nullarbor chondrites: Exposure ages, terrestrial ages, and weathering effects

“…In addition, the production rate of 14 C for small meteorites is dependent on shielding. More detailed discussions are given by Jull (2001) and Jull et al (2000).…”

Sealed Tube Combustion Method with MnO2 for AMS 14C Measurement

“…Above 46 amu, there was no detectable peak in the mass spectrum. Sulphur-dioxide and the other contaminating gases generated during the combustion are absorbed by MnO 2 or frozen in the water trap, thus, the use of silver wool used in other combustion methods is not necessary (Jull et al 2000). The test procedure was repeated with various sample types (collagen, wood, oxalic acid) and similar results were obtained.…”

“…The MnO 2 adsorbs the SO 2 , thus, silver wool was not applied (Jull et al 2000). Furthermore, a gas handling line with a special tube cracker was developed for easy and quick opening the combustion tube attached to the sealed tube graphitization method.…”

Radionuclide Studies of Stony Meteorites from Hot Deserts

“…This allows us to establish an average value of the saturated level of 14 C in this meteorite in space. We then relate this to other meteorites by normalization to the oxygen content (Jull et al 2000). Because we know that the 14 C production has a depth dependence in a meteorite, we assign a relatively conservative error of ±15% to this possible depth error.…”