Glacial and fluvial landforms record the recent history of the Earth surface and have the potential to provide information about uplift and climate changes during Quaternary times. Patagonia hosts uniquely well-preserved moraine deposits, along with outwash and fluvial terraces. This offers the possibility of determining the timing of glacier advances since the Great Patagonian Glaciation (ca. 1.2 Ma) and allows us to investigate landscape response to climate and tectonic forcing.

In this study, we present twenty-eight new in situ ¹⁰Be exposure ages for glacial deposits, outwash sediments, and fluvial terraces at the latitude of the Chile Triple Junction (∼46°30′S). We combine this database with a detailed mapping and a morphological analysis of the Deseado River terrace system. The glacial and outwash deposits document at least five major glacial advances in the Lago Buenos Aires valley before the deposition of the Moreno system during Marine Isotope Stage (MIS) 8. Key advances occurred during MIS 12 and MIS 16. Further ice expansions that resulted in Telken V and VI/VII outwash surfaces date to 780 ka and ca. 1.2 Ma respectively. Overall, our data show the difficulty of dating pre-LGM glacial deposits using surface exposure methods and reinforce the idea that outwash surfaces are better targets to determine the age of glacial sequences in the region.

The Deseado River terrace system yields stratigraphically consistent ages that range from 1167 to 447 ka, which indicate that these terraces formed during Pleistocene times. Our analysis suggests that terraces T3, T7 and T8 may have been formed during cold stages, close to the glacial-interglacial transitions. We also calculated incision rates that reveal a strong initial pulse, from ca. 1200 to 900 ka, which was followed by significantly weaker river incision pulses.

Finally, our geomorphological analysis confirms that the oldest fluvial terraces of the Deseado River system exhibit a NE-SW tilting through a broad area, next to the Atlantic Ocean. This was previously interpreted as the surface response to a long-wavelength dynamic uplift, a phenomenon that should be reassigned to the early Pleistocene.

冰川和河流的地貌记录了地球表面的最新历史，并有可能提供有关第四纪隆升和气候变化的信息。巴塔哥尼亚拥有保存完好的独特的冰m沉积物，以及冲积和河流阶地。这提供了确定自巴塔哥尼亚大冰川（约1.2 Ma）以来冰川前进时间的可能性，并使我们能够研究景观对气候和构造强迫的响应。

在这项研究中，我们提出了28个新的原位¹⁰在智利三结交界处（〜46°30′S）的冰川沉积，冲刷沉积物和河流阶地的暴露年龄。我们将此数据库与Deseado河阶地系统的详细地图绘制和形态分析相结合。在海洋同位素阶段（MIS）8期间，莫雷诺系统沉积之前，冰川和冲积沉积物记录了拉各布宜诺斯艾利斯河谷至少有5条主要的冰川进展。主要进展发生在MIS 12和MIS 16期间。 Telken V和VI / VII冲刷表面的历史可追溯到780 ka和ca。分别为1.2 Ma。总的来说，我们的数据显示了使用表面暴露方法对LGM之前的冰川沉积物进行测年的难度，并强化了这样一种观念，即外洗表面是确定该地区冰川序列年龄的更好目标。

Deseado River阶地系统产生的地层年龄一致，范围从1167年至447 ka，这表明这些阶地是在更新世时期形成的。我们的分析表明，阶地T3，T7和T8可能是在寒冷时期形成的，接近冰川-冰川间的过渡。我们还计算了从大约到大约9个切开率，这些切开率显示出很强的初始脉冲。1200至900 ka，其次是河缝脉冲明显减弱。

最后，我们的地貌分析证实，Deseado河水系中最古老的河床阶地表现出NE-SW倾斜，穿过大西洋附近的广阔区域。以前将其解释为对长波长动态隆升的表面响应，这种现象应重新分配给早更新世。