Academic Journal
Resolving the timescales of magmatic and hydrothermal processes associated with porphyry deposit formation using zircon U–Pb petrochronology
| العنوان: | Resolving the timescales of magmatic and hydrothermal processes associated with porphyry deposit formation using zircon U–Pb petrochronology |
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| المؤلفون: | Large, Simon J. E., Wotzlaw, Jörn-Frederik, Guillong, Marcel, von Quadt, Albrecht, Heinrich, Christoph A. |
| بيانات النشر: | Copernicus Publications |
| سنة النشر: | 2020 |
| المجموعة: | Niedersächsisches Online-Archiv NOA (Gottfried Wilhelm Leibniz Bibliothek Hannover) |
| مصطلحات موضوعية: | article, Verlagsveröffentlichung |
| الوصف: | Understanding the formation of economically important porphyry Cu–Au deposits requires knowledge of the magmatic-to-hydrothermal processes that act within the much larger magmatic system and the timescales on which they occur. We apply high-precision zircon geochronology (chemical abrasion–isotope dilution–thermal ionisation mass spectrometry; CA–ID–TIMS) and spatially resolved zircon geochemistry (laser ablation inductively coupled plasma mass spectrometry; LA-ICP-MS) to constrain the magmatic evolution of the underlying magma reservoir at the Pliocene Batu Hijau porphyry Cu–Au deposit. We then use this extensive dataset to assess the accuracy and precision of different U–Pb dating methods of the same zircon crystals. Emplacement of the oldest pre- to syn-ore tonalite (3.736±0.023 Ma) and the youngest tonalite porphyry to cross-cut economic Cu–Au mineralisation (3.646±0.022 Ma) is determined by the youngest zircon grain from each sample, which constrains the duration of metal precipitation to fewer than 90±32 kyr. Overlapping spectra of single zircon crystallisation ages and their trace element distributions from the pre-, syn and post-ore tonalite porphyries reveal protracted zircon crystallisation together with apatite and plagioclase within the same magma reservoir over >300 kyr. The presented petrochronological data constrain a protracted early >200 kyr interval of melt differentiation and cooling within a large heterogeneous magma reservoir, followed by magma storage in a highly crystalline state and chemical and thermal stability over several tens of thousands of years during which fluid expulsion formed the ore deposit. Irregular trace element systematics suggest magma recharge or underplating during this final short time interval. The comparison of high-precision CA–ID–TIMS results with in situ LA-ICP-MS and a sensitive high-resolution ion microprobe (SHRIMP) U–Pb geochronology data from the same zircon grains allows a comparison of the applicability of each technique as a tool to constrain dates ... |
| نوع الوثيقة: | article in journal/newspaper |
| وصف الملف: | electronic |
| اللغة: | English |
| Relation: | Geochronology -- https://www.geochronology.net/ -- 2628-3719; https://doi.org/10.5194/gchron-2-209-2020; https://noa.gwlb.de/receive/cop_mods_00053875; https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00053528/gchron-2-209-2020.pdf; https://gchron.copernicus.org/articles/2/209/2020/gchron-2-209-2020.pdf |
| DOI: | 10.5194/gchron-2-209-2020 |
| الاتاحة: | https://doi.org/10.5194/gchron-2-209-2020 https://noa.gwlb.de/receive/cop_mods_00053875 https://noa.gwlb.de/servlets/MCRFileNodeServlet/cop_derivate_00053528/gchron-2-209-2020.pdf https://gchron.copernicus.org/articles/2/209/2020/gchron-2-209-2020.pdf |
| Rights: | https://creativecommons.org/licenses/by/4.0/ ; uneingeschränkt ; info:eu-repo/semantics/openAccess |
| رقم الانضمام: | edsbas.C4FC2BC7 |
| قاعدة البيانات: | BASE |
| DOI: | 10.5194/gchron-2-209-2020 |
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