Abstract Numerical modeling coupling erosion with crustal deformation predicts that development of an orographic rain shadow may explain the asymmetric exhumation of convergent plate boundary orogens. This prediction is consistent with observations from the Southern Alps of New Zealand, where bedrock thermochronology indicates crustal exhumation has been concentrated along the wet, windward side of the mountains. While the spatial correspondence of exhumation and precipitation patterns is compelling, a robust evaluation of the link between orographic and orogenic processes further requires a temporal comparison between exhumation history, plate reconstructions and paleoclimatic records. We present a detailed exhumation history of the Southern Alps from detrital apatite and zircon fission-track thermochronology of the Waiho-1 borehole, a 3.6 km-thick sequence of proximal foreland basin sediments. Inverse thermal modeling of a 2062-grain dataset predicts two periods of rapid exhumation in the Early and Late Miocene. Rapid exhumation in the Early Miocene was synchronous with the development of transpression along the Alpine Fault and a ca. 20–22 Ma pulse of exhumation may reflect cooling during inversion of preexisting extensional basins. Rapid exhumation in the Late Miocene was not synchronous with a discrete change in plate convergence but increased exhumation rates after 7.4 Ma may instead reflect localization of plate boundary deformation along the Alpine Fault as orographic precipitation concentrated exhumation in the Alpine Fault hanging wall. We propose that, similar to prior interpretations from bedrock thermochronology, detrital thermochronology of the Southern Alps foreland basin is consistent with numerical model predictions linking asymmetric exhumation of the orogen to the growth of an orographic rain shadow.

中文翻译：

---

将新西兰南阿尔卑斯山的造山运动和地形联系起来：来自 Waiho-1 钻孔碎屑裂变径迹热年代学的新观察

摘要 侵蚀与地壳变形耦合的数值模拟预测，地形雨影的发展可以解释会聚板块边界造山带的不对称剥露。这一预测与新西兰南阿尔卑斯山的观测结果一致，那里的基岩热年代学表明，地壳剥露集中在山区潮湿的迎风面。虽然折返和降水模式的空间对应是令人信服的，但对地形和造山过程之间联系的有力评估还需要在折返历史、板块重建和古气候记录之间进行时间比较。我们从 Waiho-1 钻孔的碎屑磷灰石和锆石裂变径迹热年代学中展示了南阿尔卑斯山的详细挖掘历史，a 3。6 公里厚的近端前陆盆地沉积层序。2062 粒数据集的逆热模型预测了早中新世和晚中新世的两个快速挖掘时期。早中新世的快速挖掘与沿高山断层和约 20-22 Ma 剥脱脉冲可能反映了先前存在的伸展盆地反转期间的冷却。晚中新世的快速折返与板块收敛的离散变化不同步，但 7.4 Ma 后折返率的增加可能反映了沿高山断层的板块边界变形的局部化，因为高山断层挂壁的地形降水集中折返。我们建议，类似于基岩热年代学的先前解释，