Terrestrial ages of meteorites

Terrestrial Ages of Meteorites

The terrestrial age, or the terrestrial residence time of a meteorite, together with its exposure history provides us with useful insight into the history of the meteorite. It is easy to observe that stony meteorites can weather quickly in humid environments. However, we find that large numbers of meteorites found in semi-arid and arid environments can survive for much longer times. Meteorites ...

Terrestrial Ages of Some Meteorites from Oman

Terrestrial Ages of Antarctic Meteorites Based on the Thermoluminescence Levels Induced in the Fusion Crust

The fusion crust of eight Antarctic meteorite nds show natural thermoluminescence (TL) levels about 100 times higher than the levels in the fusion crust of freshly fallen meteorites, Dhajala, Jilin and Bansur. If it is assumed that this TL is due to cosmic ray received on the surface of Antarctica, the terrestrial residence times of the meteorites is calculated to lie between 10 10 years. Stric...

Ages and Geologic Histories of Martian Meteorites

We review the radiometric ages of the 16 currently known Martian meteorites, classified as 11 shergottites (8 basaltic and 3 lherzolitic), 3 nakhlites (clinopyroxenites), Chassigny (a dunite), and the orthopyroxenite ALH84001. The basaltic shergottites represent surface lava flows, the others magmas that solidified at depth. Shock effects correlate with these compositional types, and, in each c...

Isotopic Analyses of Barium in Meteorites and in Terrestrial Samples

Isotopic compos•tien and concentration of barium in six stone meteorites and the silicate inclusions of two iron meteorites and three terrestrial samples were measured by use of a 'double spike' isotopic dilution technique in order to correct for laboratory fractionation. Any differences between the abundances of the isotopes in meteoritic and terrestrial Ba were found to be less than 0.1% for ...