The Trans-Hudson Orogen (THO), formed from the convergence between the Superior craton and the composite Churchill Upper Plate (CUP), is one of the best-preserved examples of a collisional orogen in the Paleoproterozoic. Similar to modern collision systems such as the Himalayan orogen, it is characterized by a composite upper plate in which terrane accretion established a continental plateau that was tectonically and magmatically active for >100 myr. Our study presents new petrological and geochronological data for four samples collected in three lithotectonic domains of the south Rae craton (one of the CUP terranes). The results presented here allow us to re-define the previously proposed extent of THO reworking in the CUP and afford the opportunity to study and compare the evolution of various fragments that illustrate differing levels of a collapsed plateau in the CUP hinterland. The new data indicate that the south Rae craton locally preserves evidence for burial at 1.855–1.84 Ga with peak metamorphic conditions at approximately 790 °C and 9.5–12.5 kbar followed by rapid cooling and decompression melting (P < 6 kbar) at ca. 1.835–1.826 Ga.

These results, which provide important and so far missing Pressure-Temperature-time (P-T-t) constraints on the evolution of the south Rae craton in the Northwest Territories at Trans-Hudson time, coupled with existing regional geochronological and geochemical data, are used to propose an updated model for the post-1.9 Ga THO collision and extensional collapse. Our results reveal that: i) initial thickening in the upper plate started at Snowbird time (ca. 1.94 Ga), then continued via Sask collision (with high-grade metamorphism recorded in the south Rae craton, ca. 1.85 Ga), and ended with Superior collision (ca. 1.83 Ga); ii) the extent of the THO structural and metamorphic overprint in the SW CUP is much broader across strike than previously recognized, and iii) T-t data in the south Rae are indicative of relatively fast cooling rates (8–25 °C/Ma) compared to other known Precambrian orogens. We suggest that the Paleoproterozoic THO represents the first record of a major ‘modern-style’ orogenic plateau collapse in Earth’s history.

Trans-Hudson造山带（THO）是由上克拉通和丘吉尔复合上板（CUP）之间的汇合形成的，是古元古代碰撞造山带保存最完好的例子之一。与现代碰撞系统（如喜马拉雅造山带）相似，它的特征在于复合上板，在该复合板中，地层积聚形成了一个大陆高原，该大陆高原在构造和岩浆活动中作用大于100迈尔。我们的研究提出了在南雷克拉通（CUP地形之一）的三个岩石构造域中收集的四个样本的新岩石学和年代学数据。此处提供的结果使我们能够重新定义CUP中THO重做的范围，并有机会研究和比较各种片段的演变，这些片段说明了CUP腹地塌陷高原的不同水平。新数据表明，南雷克拉通局部保留了埋藏在1.855–1.84 Ga处的证据，并在大约790°C和9.5–12.5 kbar处出现了峰值变质条件，随后在大约75°C进行了快速冷却和减压融化（P <6 kbar）。1.835–1.826 Ga。

这些结果使用了Trans-Hudson时间对西北地区南Rae克拉通的演化提供了重要且迄今尚无的压力-温度-时间（PT- t）约束，并使用了现有的区域地质年代和地球化学数据为1.9 Ga THO之后的碰撞和伸展塌陷提出更新模型。我们的结果表明：i）上板块的初始增厚始于雪鸟时期（约1.94 Ga），然后通过萨斯克碰撞（在Rae克拉通南部记录的高变质作用，约1.85 Ga）继续，直到结束具有卓越的碰撞力（约1.83 Ga）；ii）SW CUP中THO结构和变质叠印的范围比以前认识到的要广泛得多，并且iii）T- t与其他已知的前寒武纪造山带相比，南雷地区的数据表明冷却速度相对较快（8-25°C / Ma）。我们建议古元古代THO代表地球历史上一次重大的“现代式”造山带高原崩塌的第一个记录。