Abstract In this contribution, we present field-based evidence that in the Mary Kathleen Domain from the Eastern Fold Belt of the Mount Isa Inlier the 1790-1750 Ma metasediments of the Leichhardt Superbasin were sheared and folded between 1750-1710 Ma. The Mary Kathleen Domain consists of a series of anastomosing high and low strain domains intruded syn- to late-tectonically by a series of 1740-1710 Ma felsic and mafic plutons and dykes. The timing relationships in the high strain domains are unclear due to mylonitisation and transposition but in the lower strain domains are well-preserved. The earliest deformation, D1, consists of a series of low angle truncation surfaces and shear zones that are folded around large scale N-S trending upright folds during D2. The D2 folds were refolded during D3 along NW to EW trending fold axes. An undeformed granitic pluton from the Mt Godkin area dated at ∼1710 Ma that crosscuts the D2-D3 folds and the youngest detrital zircon population of ∼1750 Ma constrains the timing of D1-D3 deformation between 1750 and 1710 Ma. Later, N-S (D4) and N-E (D5) trending brittle-ductile shears are interpreted to indicate a late Isan Orogeny overprint. The occurrence of contemporaneous folding in the Western Fold Belt suggests that between 1750 and 1710 Ma the eastern margin of the North Australia Craton was experiencing a significant deformation event that can be correlated with similarly aged deformation events from other parts of the North Australia Craton, from South Australia Craton and from East Antarctica. Following the assembly of most of the Nuna Supercontinent by 1.8 Ga, we postulate that the 1750-1710Ma deformation and plutonism observed in Mount Isa Inlier is part of a series of worldwide orogenic events that contributed to the final configuration of the Nuna Supercontinent.

中文翻译：

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1750-1710 Ma 沿北澳大利亚克拉通东缘的变形

摘要 在这篇文章中，我们提供了基于实地的证据，表明在 Isa Inlier 东部褶皱带的 Mary Kathleen 域中，Leichhardt Superbasin 的 1790-1750 Ma 变沉积物在 1750-1710 Ma 之间被剪切和折叠。Mary Kathleen 域由一系列 1740-1710 Ma 长英质和镁铁质深成岩体和岩脉在构造上从同步到晚期侵入的一系列吻合的高应变域和低应变域组成。由于 mylonitisation 和转座，高应变域中的时间关系尚不清楚，但在低应变域中保存完好。最早的变形 D1 由一系列低角度截断面和剪切区组成，这些区域在 D2 期间围绕大规模 NS 趋势直立褶皱折叠。D2 折叠在 D3 期间沿 NW 到 EW 趋势折叠轴重新折叠。来自 Mt Godkin 地区的未变形花岗质岩体，其年代为 ~1710 Ma，它横切 D2-D3 褶皱，最年轻的碎屑锆石群为 ~1750 Ma，限制了 D1-D3 变形时间在 1750 至 1710 Ma 之间。后来，NS (D4) 和 NE (D5) 趋势的脆性-韧性剪切被解释为表明晚期 Isan 造山运动叠印。西部褶皱带同时期褶皱的发生表明，在 1750 至 1710 Ma 之间，北澳大利亚克拉通东缘正在经历一次重大变形事件，这可能与来自北澳大利亚克拉通其他地区的类似年龄变形事件相关联，从南澳大利亚克拉通和南极洲东部。在努纳超大陆的大部分组装了 1.8 Ga 之后，