The Archean to Paleoproterozoic transition as recovered in the FAR DEEP cores: LA-ICP-MS U-Pb geochronology of detrital zircons and accompanying provenance analysis of siliciclastic sedimentary rocks

远深岩心中发现的太古代到古元古代的过渡：碎屑锆石的 LA-ICP-MS U-Pb 地质年代学和硅质碎屑沉积岩的相关物源分析

• 批准号: 75363574
• 负责人: Professor Dr. Hans Heinrich Bahlburg
• 金额: --
• 依托单位: Institut für Geologie und Paläontologie
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2012-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/75363574?language=en
• 关键词: Archean; Paleoproterozoic; transition; recovered; FAR

During the Archaean-Palaeoproterozoic transition many global environmental changes occurred in the Earth’s system at the same time as tectonic reorganisations led to the break-up of the supercontinent Kenorland. Stratigraphic successions registering these events were successfully drilled in northern Russia (Fennoscandia) in the FAR-DEEP/ICDP project. - The first part of our study aimed at improving age constraints by Laser Ablation ICP-MS U-Pb geochronology on detrital zircons for three of these events recorded in the FAR DEEP cores. The events are the Huronian glaciation, the Lomagundi-Jatuli positive excursion of δ13C, and the Shunga event of enhanced deposition of Corg-rich sediments. Our data resulted in tighter temporal constraints for these events. In rocks marking the transition from the Lomagundi-Jatuli to the Shunga event we also found U-Pb ages, now confirmed by ID-TIMS, which are too young regarding their stratigraphic position, and which are difficult to explain in view of the allegedly undisturbed stratigraphic succession. These need to be verified by additional analyses.- Also, the provenance of the analysed zircons and the nature of the recycled, partly Palaeoarchaean crust will be established by LA ICP-MS Hf isotope analysis on dated zircons and by ion microprobe analysis of heavy minerals like tourmaline and rutile.

在古细菌 - 帕克（Tector）的同时，在地球系统中发生了许多全球性的变化。 。这些事件的增强量需要通过其他分析来验证。-此外，分析的锆石的出处以及可回收的，部分的palaeoarchaean壳的性质将由已过时的RCONS和ION MIRCOROBE分析（例如重型矿物）建立。电气石和金红石。