Zircon geochronology of the Paleoproterozoic Magondi Supergroup in Zimbabwe: Age constraints to the Lomagundi-Jatuli event.
Zircon geochronology of the Paleoproterozoic Magondi Supergroup in Zimbabwe: Age constraints to the Lomagundi-Jatuli event.
复制标题
津巴布韦古元古代马贡迪超群的锆石地质年代学：Lomagundi-Jatuli 事件的年龄限制。
作者：
Sawada;H.;Mugandani;E.;Sato;T.;Sawaki;Y.;Sakata;S.;Isozaki;Y.;Maruyama;S.
约。 2.2–2.1 南部非洲津巴布韦克拉通的Ga Magondi超群主要由沉积在裂谷盆地/被动大陆边缘的沉积岩组成，记录了一个独特的碳同位素扰动事件，称为Lomagundi-Jatuli事件（LJE）。这项研究报告了来自马贡迪超群的 Deweras 和 Lomagundi 群的碎屑锆石以及来自底层花岗岩类的火成锆石的新 U-Pb 年龄，以限制 LJE 的时间并确定马贡迪超群的起源。大多数分析的碎屑锆石颗粒的年龄范围约为2.9 和 2.6 Ga。大约三。 Deweras群砂岩中2.3~2.2 Ga碎屑锆石，最年轻的207Pb-206Pb年龄为2,216±22 Ma，表明津巴布韦克拉通LJE的爆发几乎与Fennoscandia和上克拉通同时发生，支持了LJE的全球同步性。
The ca. 2.2–2.1 Ga Magondi Supergroup on the Zimbabwe Craton in Southern Africa is mainly composed of sedimentary rocks deposited in a rift basin/passive continental margin, which record a unique episode in carbon isotope perturbation called the Lomagundi–Jatuli Event (LJE). This study reports new U–Pb ages of detrital zircons from the Deweras and Lomagundi groups of the Magondi Supergroup, and of igneous zircons from underlying granitoids, to constrain the timing of the LJE and to identify the provenance of the Magondi Supergroup. Most analysed detrital zircon grains range in ages between ca. 2.9 and 2.6 Ga. Three ca. 2.3–2.2 Ga detrital zircons from sandstone of the Deweras Group, with the youngest207Pb‐206Pb age of 2,216 ± 22 Ma, indicate the onset of LJE in the Zimbabwe Craton was almost simultaneous to that in Fennoscandia and the Superior Craton, supporting the global synchronicity of the LJE.