Department of Geosciences, University of Tübingen, Tübingen, Germany.
Science. 2013 Aug 16;341(6147):774-6. doi: 10.1126/science.1239132.
Canyon incision into mountain topography is commonly used as a proxy for surface uplift driven by tectonic or geodynamic processes, but climatic changes can also instigate incision. The ~1250-kilometer (km)-long eastern margin of the Andean Plateau hosts a series of 1.5- to 2.5-km-deep canyons that cross major deformation zones. Using (U-Th)/He thermochronology, we document a transition from Miocene faulting to Pliocene canyon incision across the northeastern plateau margin. Regionally, widespread Pliocene incision into the eastern plateau margin is concurrent with a shift in global climate from early Pliocene warmth to late Pliocene cooling. Enhanced moisture transport onto the Andean Plateau driven by sea surface temperature changes during cooling is the likely pacemaker for canyon incision.
峡谷在山地形中的切入通常被用作构造或地球动力学过程驱动的地表抬升的代理，但气候变化也可以引发切入。安第斯高原的~1250 公里（km）长的东部边缘有一系列 1.5 到 2.5 公里深的峡谷，穿过主要的变形带。利用（U-Th）/He 热年代学，我们记录了从中新世断层到上新世峡谷切入的转变，横跨东北高原边缘。在区域上，上新世广泛切入高原东部边缘与全球气候从早更新世温暖到晚更新世冷却的转变同时发生。变冷期间海表温度变化驱动的增强的水汽输送到安第斯高原上，可能是峡谷切入的起搏器。
