Direct dating of gold by radiogenic helium radiometric dating geology lab
Only exceptionally, natural gold accumulates enough Re to allow the direct dating of gold using the decay of He method gave geologically reasonable results (Eugster et al., 1992; Niedermann et al., 1993), but had problems with excess He from fluid inclusions (Eugster et al., 1995; Pettke et al., 1997).
However, a new step-heating technique and recent advances in high-sensitivity mass spectrometry have allowed successful application of the U/Th–He method to age determinations of archaeological artifacts of gold (Eugster et al., 2009).
Our usually reliable day-to-day sensibilities tell us that such things can't happen, but they can and do happen because solid rock reveals its malleability only over time scales very long compared to human eventstypically in spans of tens of thousands if not millions of years.
Given enough time, cold surface rock will yield to flowing water and buried rock will bend or even flow rather than break.
Authenticating archaeological gold objects is a major problem, as gold is probably the most difficult material in terms of detecting modern forgeries.
In 1996 we published the results of the study of faked and genuine gold crystals from the Santa Elena gold mine in Venezuela, and demonstrated that the U/Th – He dating method is a powerful tool for detecting forgeries among gold objects.
It is a silvery-white metal in the actinide series of the periodic table.
A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons.
La mesure de l’U, du Th et de l’He permet de déterminer le moment de départ du processus de piège de l’He.Since these inclusions are submicrometer-sized, the radiogenic helium formed in them is not accumulated but implanted in the structure of native gold, which suggests its good preservation over billions of years. This suggestion was experimentally supported by the investigation of the kinetics of radiogenic helium release from native gold. These ages tie the Diamantina gold mineralization to the Brasiliano orogenic event, in the context of the Gondwana amalgamation.Our results indicate that U/Th– The radiometric dating of gold deposits almost invariably requires the assumption that datable minerals, e.g., monazite and arsenopyrite, are coeval with the gold with which they are spatially associated.