تقرير
Mechanical twinning of monazite expels radiogenic Pb
| العنوان: | Mechanical twinning of monazite expels radiogenic Pb |
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| المؤلفون: | D. Fougerouse, S. M. Reddy, A.-M. Seydoux-Guillaume, C. L. Kirkland, T. M. Erickson, D. W. Saxey, W. D. A. Rickard, D. Jacob, H. Leroux, C. Clark |
| المصدر: | Geology. 49(4) |
| بيانات النشر: | United States: NASA Center for Aerospace Information (CASI), 2020. |
| سنة النشر: | 2020 |
| مصطلحات موضوعية: | Geosciences (General) |
| الوصف: | Mechanical twins form by the simple shear of the crystal lattice during deformation In order to test the potential of narrow twins in monazite to record the timing of their formation, a ~1,700 Ma monazite grain deformed at ~980 Ma was investigated by electron backscattered diffraction (EBSD), transmission electron microscopy (TEM) and atom probe tomography (APT). APT 208Pb/232Th ages indicate that the twin was entirely reset by radiogenic Pb-loss during its formation at conditions far below the monazite closure temperature. The results are consistent with a model where Pb is liberated during rupture of REE-O bonds in the large REEO9 polyhedra during twinning. Liberated Pb is likely to migrate along fast diffusion pathways such as crystal defects. The combination of a quantitative microstructural investigation and nanogeochronology provides a new approach for understanding the history of accessory phases. |
| نوع الوثيقة: | Report |
| اللغة: | English |
| تدمد: | 1943-2682 0091-7613 |
| DOI: | 10.1130/G48400.1 |
| URL الوصول: | https://ntrs.nasa.gov/citations/20210000736 |
| ملاحظات: | 81107 nnj13ha01c |
| رقم الأكسشن: | edsnas.20210000736 |
| قاعدة البيانات: | NASA Technical Reports |
| تدمد: | 19432682 00917613 |
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| DOI: | 10.1130/G48400.1 |