.png){kind=icon}
返回
Pb diffusion in zircon
.png){kind=icon}
PRE
AI
DOI：10.1016/S0009-2541(00)00233-3.png)
.png){kind=icon}
原文求助.png){kind=icon}
分享.png){kind=icon}
收藏
摘要
En 中文
Diffusion of Pb was characterized in natural and synthetic zircon under a range of conditions. In most experiments, mixtures of Pb sulfate and ground zircon were used as the sources of diffusant, with Pb depth profiles measured with Rutherford Backscattering Spectrometry (RBS). As complement to these in-diffusion experiments, out-diffusion experiments were run on both synthetic Pb-doped and natural zircon with relatively high Pb concentrations, and analyzed with either electron microprobe or RES. Over the temperature range 1000-1500 degreesC, the following Arrhenius relation was obtained: D = 1.1 x 10(-1) exp( - 550 +/- 30 kJ mol(-1)/RT) m(2) s(-1) Results for diffusion in natural and synthetic zircon were quite similar, as are those for in- and out-diffusion. Pb diffusion does not appear to be strongly influenced by pressure, crystallographic orientation, or the presence of water. The slow diffusion rate for Pb indicates that Pb isotope ratios will not be altered by volume diffusion in crystalline zircon under most geologic conditions, a finding consistent with the frequent observation of inheritance and preservation of multistage histories in zircon. Most Pb loss in zircon, then, is likely a consequence of recrystallization or Pb transport in zircons with severe radiation damage (although the latter can be effective only for vast annealing times at very low temperatures). Mean closure temperatures, calculated from the diffusion parameters, are in excess of 900 degreesC for zircons of typical size, a result in consonance with field-based estimates of closure temperatures. (C) 2000 Elsevier Science B.V. All rights reserved.
Keyword:
Rutherford Backscattering Spectrometry
arrhenius relation
Pb zircon diffusion
期刊
IF:
3.6
论文数:
9.4K
被引数:
4.5W
机构
暂无机构信息
引用论文
.png){kind=icon}
Social participation of relatives post-stroke: the role of rehabilitation and related ethical issues
PREAI
分享收藏Effect of Dielectric Relaxation of Epoxy Resin on Dielectric Loss of Medium-Frequency Transformer
PREAI
分享收藏
查看更多内容