近日，美国匹兹堡大学Jennie Plasterr团队研究了秘鲁安第斯山脉峡谷切口的驱动因素：构造学，降水和排水盆地捕获。该项研究成果发表在2025年11月7日出版的《科学进展》杂志上。

在海拔约3.7千米的安第斯高原上，发育着深达2-3千米的峡谷，其形成机制一直存在争议——既有观点认为高原表面隆升是主因，也有学者主张降水增强侵蚀作用才是关键。

研究组将地表过程模型与已发表的构造地质参数（包括基于剖面的构造几何形态、运动学特征和缩短速率）以及全球大气环流模型得出的降水估算相结合，系统评估了构造活动产生的几何形态、序列断层运动及相应地表隆升能否再现高原现今地貌特征。

模拟显示：在断层抬升速率超过河流下切速率的区域会形成内流盆地。约10 Ma以来构造缩短速率减缓，使得河流侵蚀力能够与构造隆升相抗衡，并开始下切高原边缘的内流盆地。模型再现的两次流域袭夺事件（约7-5 Ma和约3.5-0.5 Ma）与气候驱动的流量波动共同作用，显著增强了河流径流量、侵蚀力和输沙能力，从而促进峡谷下切。这一发现揭示了流域袭夺过程在安第斯高原东北缘峡谷形成中的重要作用。

附：英文原文

Title: Drivers of canyon incision in the Peruvian Andes: Tectonics, precipitation, and drainage basin capture

Author: Jennie Plasterr, Nadine McQuarrie, Eitan Shelef, Sarah Falkowski, Paul R. Eizenhfer, Todd A. Ehlers

Issue&Volume: 2025-11-07

Abstract: The drivers behind the marked 2- to 3-km relief canyons carved into the ca. 3.7-km-high Andean Plateau remain debated, with proposed triggers ranging from plateau surface uplift to precipitation-enhanced erosion. We integrate a surface processes model with published cross-section–derived estimates of structural geometry, kinematics, and shortening rates, as well as precipitation estimates from global atmospheric circulation models, to assess whether the geometry, sequential fault motion, and resulting surface uplift can reproduce plateau morphology. Endorheic basins form where uplift on faults exceeds incision. A decrease in shortening after ~10 Ma allows rivers to compete with uplift and incise into endorheic basins at the plateau edge. Two modeled basin capture events at ~7 to 5 Ma and ~3.5 to 0.5 Ma, coupled with climate-driven discharge fluctuations, markedly increase rivers’ discharge, erosion, and sediment transport, facilitating canyon incision and highlighting the importance of basin captures in canyon formation along the northeastern edge of the Andean Plateau.

DOI: adz9285

Source: https://www.science.org/doi/10.1126/sciadv.adz9285