Breakthrough of 2- to 3-μm scale U–Pb zircon dating using Cameca IMS-1280HR SIMS |
| |
Authors: | Yu Liu Xian-Hua Li Qiu-Li Li Guo-Qiang Tang |
| |
Institution: | State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China |
| |
Abstract: | A zircon U–Pb dating method with a high spatial resolution of 2- to 3-μm was successfully implemented by using Cameca IMS-1280HR SIMS in this study. Homemade cathode and modified intermediate pole were used to improve the intrinsic performance of duoplasmatron ion source. An O− primary beam with intensity of approximately 3 μA and stability of 0.68% over 40 minutes was achieved and could be used continuously for more than 240 hours under high current conditions. Under Gaussian illumination mode, a 2- to 3-μm O− primary beam was obtained with an intensity of approximately 200 pA. Four standard zircons, namely, 91500, Temora, Plešovice, and Qinghu, were dated using the 2- to 3-μm high spatial resolution U–Pb isotopic analysis, yielding U–Pb ages consistent with their recommended values, within errors. Our work shows that zircon U–Pb dating with high accuracy and spatial resolution can be achieved, on the basis of a series of duoplasmatron modification and instrumental optimization. |
| |
Keywords: | high spatial resolution SIMS U–Pb dating zircon |
|
|