Secular changes in the architecture, thermal state, and metamorphic style of global orogens are thought to have occurred since the Archean; however, despite widespread research, the driving mechanisms for such changes remain unclear. The Paleoproterozoic may prove to be a key era for investigating secular changes in global orogens, as it marks the earliest stage of an eon that saw the onset of modern‐style global tectonics. The 2.1 Ga granulite‐facies Mistinibi‐Raude Domain (MRD), located in the Southeastern Churchill Province, Canada, offers a rare exposure of Paleoproterozoic high metamorphic grade supracrustal sequences (Mistinibi Complex, MC). Rocks from this domain were subjected to petrochronological investigations to establish P–T–t–X evolutions and to provide first order thermal state, burial and exhumation rates, and metamorphic gradients for the transient Paleoproterozoic times. To obtain comprehensive insight into the P–T–t–X evolution of the MRD, we used multi‐method geochronology—Lu–Hf on garnet and U–Pb on zircon and monazite—integrated with detailed petrography, trace element chemistry, and phase equilibria modelling. Despite the extensive use of zircon and monazite as geochronometers, their behaviour in anatectic conditions is complex, leading to substantial ambiguity in interpreting the timing of prograde metamorphism. Our results indicate a clockwise metamorphic path involving significant melt extraction from the metasedimentary rocks, followed by cooling from >815°C to ~770°C at ~0.8 GPa. The timing of prograde burial and cooling from supra‐ to subsolidus conditions is constrained through garnet, monazite, and zircon petrochronology at 2,150–2,120 Ma and at 2,070–2,080 Ma, respectively. These results highlight long‐lived residence of the rocks at mid‐crustal supra‐solidus conditions (55–70 Ma), with preserved prograde and retrograde supra‐solidus monazite and zircon. The rocks record extremely slow burial rates (0.25–0.30 km/Ma) along a high metamorphic gradient (900–1,000°C/GPa), which appears symptomatic of Paleoproterozoic orogens. The MC did not record any significant metamorphism after 2,067 Ma, despite having collided with terranes that record high‐grade metamorphism during the major 1.9–1.8 Ga Trans‐Hudson orogeny. The MC would therefore represent a remnant of a local early Paleoproterozoic metamorphic infrastructure, later preserved as superstructure in the large hot Trans‐Hudson orogen.

中文翻译：

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c。完整的变质周期和长寿命的厌食症 2.1加拿大嘎斯提尼比比综合大楼

自从太古宙以来，全球造山带的结构，热态和变质方式发生了长期变化。然而，尽管进行了广泛的研究，但这种变化的驱动机制仍不清楚。古元古代可能被证明是研究全球造山带世俗变化的关键时代，因为它标志着见证现代全球全球构造学问世的最早阶段。位于加拿大东南丘吉尔省的2.1 Ga粒岩相Mistinibi-Raude域（MRD）罕见地暴露了古元古代高变质级上地壳层序（Mistinibi Complex，MC）。对来自该领域的岩石进行了岩石年代学研究，以建立P – T – t – X演化并为古元古代瞬态提供一阶热态，埋葬和发掘速率以及变质梯度。全面了解P – T – t – X在MRD的演化过程中，我们使用了多种方法的年代学方法（石榴石上的Lu-Hf和锆石和独居石上的U-Pb），并结合了详细的岩相学，痕量元素化学和相平衡模型。尽管锆石和独居石广泛用作天文钟，但它们在强酸条件下的行为却很复杂，导致在解释渐进变质的时间方面存在很大的歧义。我们的结果表明，顺时针变质路径涉及从准沉积岩中大量提取熔体，然后在〜0.8 GPa下从> 815°C冷却至〜770°C。从石榴石，独居石和锆石的岩石年代学分别限制了从超固相到亚固相状态的前期埋葬和降温的时间，分别为2,150–2,120 Ma和2,070–2,080 Ma。这些结果突出了岩石在中地壳超固相条件下（55-70 Ma）的长期滞留，以及超固相和独居石和锆石的保存。这些岩石沿高变质梯度（900–1,000°C / GPa）记录了极慢的埋藏速率（0.25–0.30 km / Ma），这似乎是古元古代造山运动的症状。尽管在1.9-1.8 Ga Trans-Hudson重大造山过程中与记录高等级变质的地层相撞，MC在2,067 Ma之后仍未记录到任何明显的变质。因此，MC代表了当地早期古元古代变质基础设施的残余，后来被保留为大型热跨哈德逊造山带中的上层构造。这些岩石沿高变质梯度（900–1,000°C / GPa）记录了极慢的埋藏速率（0.25–0.30 km / Ma），这似乎是古元古代造山运动的症状。尽管在1.9-1.8 Ga Trans-Hudson重大造山过程中与记录高等级变质的地层相撞，MC在2,067 Ma之后仍未记录到任何明显的变质。因此，MC代表了当地早期古元古代变质基础设施的残余，后来被保留为大型热跨哈德逊造山带中的上层构造。这些岩石沿高变质梯度（900–1,000°C / GPa）记录了极慢的埋藏速率（0.25–0.30 km / Ma），这似乎是古元古代造山运动的症状。尽管在1.9-1.8 Ga Trans-Hudson重大造山过程中与记录高等级变质的地层相撞，MC在2,067 Ma之后仍未记录到任何明显的变质。因此，MC代表了当地早期古元古代变质基础设施的残余，后来被保留为大型热跨哈德逊造山带中的上层构造。8 Ga Trans-Hudson造山运动。因此，MC代表了当地早期古元古代变质基础设施的残余，后来被保留为大型热跨哈德逊造山带中的上层构造。8 Ga Trans-Hudson造山运动。因此，MC代表了当地早期古元古代变质基础设施的残余，后来被保留为大型热哈德森造山带。