Abstract The Mount Gee Sinter and the Radium Ridge Breccia within the Mount Painter Inlier, South Australia, preserve evidence of a hydrothermal event peaking during the Late Devonian (ca 365 Ma). Prior to this study, limited data relating to this event were available, but our results of 846 LA-ICPMS U–Pb monazite analyses indicate the timing of this hydrothermal event. The dominant monazite population age of ca 363 Ma for the Mount Gee Sinter represents earlier phases of a protracted hydrothermal–epithermal system, whereas a later epithermal phase cross-cuts rocks hosting ca 220 Ma age zircon. Parts of the Radium Ridge Breccia have been recently interpreted as a series of Early Cretaceous glacial events. Zircon ages (604 zircon analyses) from the Radium Ridge Breccia define a detrital population dominated by ca 1585 Ma ages, consistent with derivation of clasts within the breccia from local granitic and metasedimentary basement. The Radium Ridge Breccia is, however, dominated by a ca 367 Ma aged monazite population, probably reflecting overprinting of the local Mesoproterozoic granitic basement rock during the same hydrothermal event as formed the earlier phase of the Mount Gee Sinter. It is interpreted that the monazite ca 365 Ma age reflects a significant Late Devonian hydrothermal event, evidenced locally in the southern Mount Painter Inlier, resulting from localised heat flow but with thermal implications for the regional geology of the northwestern Curnamona Province.

中文翻译：

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U-Pb 年代学揭示了南澳大利亚弗林德斯山脉北部的 Mount Painter Inlier 内的晚泥盆世热液事件和长期热液-低温热液系统的证据

摘要 南澳大利亚芒特派特因利尔内的吉恩山和镭山脊角砾岩保存了在晚泥盆世（约 365 Ma）达到顶峰的热液事件的证据。在此研究之前，与此事件相关的数据有限，但我们的 846 LA-ICPMS U-Pb 独居石分析结果表明了此热液事件的时间。Mount Gee Sinter 的主要独居石种群年龄约为 363 Ma，代表了长期热液-超热系统的早期阶段，而后期的超热液阶段则横切岩石，其中包含约 220 Ma 年龄的锆石。部分镭岭角砾岩最近被解释为一系列早白垩世冰川事件。来自镭角角砾岩的锆石年龄（604 次锆石分析）定义了一个以约 1585 Ma 年龄为主的碎屑群，与来自当地花岗岩和变沉积基底的角砾岩内碎屑的推导一致。然而，镭岭角砾岩主要由大约 367 Ma 年龄的独居石种群主导，这可能反映了当地中元古代花岗岩基岩在与吉山烧结矿早期形成的同一热液事件中的叠印。据解释，独居石约 365 Ma 年龄反映了重要的晚泥盆世热液事件，在南部 Mount Painter Inlier 局部得到证明，由局部热流产生，但对库纳莫纳省西北部的区域地质具有热影响。可能反映了在同一个热液事件中当地中元古代花岗岩基岩的叠印，形成了吉斯山的早期阶段。据解释，独居石约 365 Ma 年龄反映了重要的晚泥盆世热液事件，在南部 Mount Painter Inlier 局部得到证明，由局部热流产生，但对库纳莫纳省西北部的区域地质具有热影响。可能反映了当地中元古代花岗岩基岩在与吉斯山早期形成的同一热液事件中的叠印。据解释，独居石约 365 Ma 年龄反映了重要的晚泥盆世热液事件，在南部 Mount Painter Inlier 局部得到证明，由局部热流产生，但对库纳莫纳省西北部的区域地质具有热影响。