Radiometric dating meteorites
In many cases, there are independent cues (such as geologic setting or the chemistry of the specimen) which can suggest that such assumptions are entirely reasonable.
However, the methods must be used with care -- and one should be cautious about investing much confidence in the resulting age...
At this temperature the composition of the kamacite would be about 4% nickel.
In the north, not far from Grootfontein is the Hoba Meteorite which is the largest knownof metal meteorite in the world, and beautifully displayed right in the middle of Windhoek are a selection of the Gibeon Meteorites, which are the largest known shower of extra terrestrial bodies ever to land on Earth.
The X-axis of the graph is the ratio of in a closed system over time.
It is not easily explained, in the general case, in any other way.
especially in absence of cross-checks by different methods, or if presented without sufficient information to judge the context in which it was obtained.
Isochron methods avoid the problems which can potentially result from both of the above assumptions.