The mining district of Nefza-Sejnane (Tunisia) encloses numerous ores and raw material deposits, all formed in relation with successive Fe-rich fluids of meteoric and/or hydrothermal origins. Here, for the first time in Tunisia, (U-Th)/He ages were obtained on supergene goethite from various localities/deposits of the district highlight direct dating of significant weathering episodes during late Tortonian and late Pleistocene. These weathering events are most likely associated with favorable conditions that combine (i) wet climate displaying sufficient meteoric water/fluid; and (ii) regional exhumation, due to large-scale vertical lithospheric movements enhancing the percolation of fluids. Matched with previous works, these results refine the stratigraphic frame for the polymetallic mineralization and clay deposits in the district, confirming the influence of meteoric fluids circulation during the late Cenozoic. As a consequence of the new (U-Th)/He data, we moreover propose a taxonomic and stratigraphic revision of the well-known mammalian fauna from the Fe-rich Douahria locality, suggesting an early Tortonian age for the fossils, i.e., prior to the first episode of meteoric event in the area.

中文翻译：

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Nefza-Sejnane区（突尼斯）的超基因铁（羟基）氧化物的（U-Th）/ He约会：成矿作用和哺乳动物生物地层学的新见解

Nefza-Sejnane（突尼斯）的采矿区围封了许多矿石和原料矿床，这些矿床和原料矿床都是与连续的富含铁的流变和/或热液源流体形成的。在这里，这是突尼斯的第一次，从该地区的各个地方/矿床获得的超基因针铁矿获得了（U-Th）/ He年龄，这突显了Tortonian晚期和更新世晚期重要的风化事件的直接年代。这些风化事件很可能与以下有利条件有关：（i）潮湿的气候显示出充足的水/流体；（ii）由于大型垂直岩石圈运动增强了流体的渗滤作用，导致了区域发掘。与先前的工作相吻合，这些结果完善了该地区多金属矿化和粘土沉积的地层框架，证实了新生代晚期陨石循环的影响。由于有了新的（U-Th）/ He数据，我们还建议对富Fe的Douahria地区著名的哺乳动物区系进行分类学和地层学修订，这表明该化石的早期Tortonian年龄，即到该地区的第一颗陨石事件。