Occurrences of Excess 40Ar in Hydrothermal Tourmaline: Interpretations from 40Ar‐39Ar Dating Results by Stepwise Heating

Autor: Huaning, QIU, Zhiping, PU, Tongmo, DAI
Zdroj: Acta Geologica Sinica; June 2007, Vol. 81 Issue: 3 p510-516, 7p
Abstrakt: Abstract:The occurrences of excess 40Ar within a hydrothermal tourmaline is discussed in term of the analysis data of syngenetic muscovite and tourmaline from the Lushui hydrothermal tin‐tungsten deposit in western Yunnan, China, using the 40Ar‐39Ar stepwise heating technique. About 80% excess 40Ar was released in the last step when the tourmaline was fused, corresponding to a release of only ∼‐3% 39Ar (K), which indicates that most excess 40Ar was held in the mineral lattice rather than in the channels parallel to the Z‐axis. This suggests that the excess 40Ar was incorporated during crystallization and not diffused into the tourmaline during the post‐crystallization history.
Databáze: Supplemental Index