Olierook Hugo K H, Fougerouse Denis, Doucet Luc S, Liu Yebo, Rayner Murray J, Danišík Martin, Condon Daniel J, McInnes Brent I A, Jaques A Lynton, Evans Noreen J, McDonald Bradley J, Li Zheng-Xiang, Kirkland Christopher L, Mayers Celia, Wingate Michael T D
Timescales of Mineral Systems Group, School of Earth and Planetary Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.
John de Laeter Centre, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.
Nat Commun. 2023 Sep 19;14(1):5274. doi: 10.1038/s41467-023-40904-8.
Argyle is the world's largest source of natural diamonds, yet one of only a few economic deposits hosted in a Paleoproterozoic orogen. The geodynamic triggers responsible for its alkaline ultramafic volcanic host are unknown. Here we show, using U-Pb and (U-Th)/He geochronology of detrital apatite and detrital zircon, and U-Pb dating of hydrothermal titanite, that emplacement of the Argyle lamproite is bracketed between 1311 ± 9 Ma and 1257 ± 15 Ma (2σ), older than previously known. To form the Argyle lamproite diatreme complex, emplacement was likely driven by lithospheric extension related to the breakup of the supercontinent Nuna. Extension facilitated production of low-degree partial melts and their migration through transcrustal corridors in the Paleoproterozoic Halls Creek Orogen, a rheologically-weak rift zone adjacent to the Kimberley Craton. Diamondiferous diatreme emplacement during (super)continental breakup may be prevalent but hitherto under-recognized in rift zones at the edges of ancient continental blocks.
阿盖尔是世界上最大的天然钻石产地，却是仅有的少数赋存于古元古代造山带中的经济矿床之一。其碱性超镁铁质火山岩宿主的地球动力学触发因素尚不清楚。在此，我们利用碎屑磷灰石和碎屑锆石的U-Pb和（U-Th）/He地质年代学以及热液钛铁矿的U-Pb定年，表明阿盖尔钾镁煌斑岩的侵位年龄范围在1311±9 Ma至1257±15 Ma之间（2σ），比之前所知的年龄更老。为形成阿盖尔钾镁煌斑岩岩筒复合体，侵位作用可能是由与超大陆努纳裂解相关的岩石圈伸展驱动的。伸展作用促进了低度部分熔融体的产生及其通过古元古代哈尔斯溪造山带中的跨地壳通道的运移，该造山带是一个与金伯利克拉通相邻的流变学上较弱的裂谷带。在（超）大陆裂解期间含金刚石岩筒的侵位可能很普遍，但迄今在古代大陆块边缘的裂谷带中未得到充分认识。
