Climate changes related to orographic barrier uplift have been in the research spotlight over recent years. Several works have focused on the interactions between climatic and tectonic processes in order to understand the development of a rain shadow. Patagonia is an ideal region in which to analyze such interactions, since a Miocene climate change, from wetter to drier conditions, has mainly been associated with Andean uplift. In this work, we analyzed a succession of stacked paleosols recorded in a Miocene North Patagonian foreland basin in order to understand how the paleosol moisture regime related to the atmospheric humidity changes caused by the uplift of the Patagonian Andes. Based on macromorphological, micromorphological, and geochemical studies, and supported by a high-resolution chronostratigraphic scheme based on U-Pb geochronology and magnetostratigraphy, the paleosols were characterized with corresponding mean annual paleoprecipitation (MAP) and mean annual temperature values. Alfisol-like paleosols were identified at the base of the foreland infill (15–14.6 Ma) with a MAP of 1229 ± 108 mm/yr. The Andisol-like paleosols recognized in the middle section of the sequence (14.6–12.75 Ma) exhibited a MAP of 1053 ± 108 mm/yr, whereas the Aridisol-like paleosols occurring in the upper section of the infill (12.75–11.5 Ma) presented a MAP of 677 ± 108 mm/yr. The determined Miocene mean annual temperatures (∼11 ± 2.1 °C) were similar to the present-day values (11 °C). Based on the complete tectonic record of the Patagonian Andes, the observed decrease in MAP was assigned to the rain shadow effect created by the uplift of the North Patagonian Andes. Results indicate that although the process started around 19 Ma, the rain shadow effect was not effectively recorded before ca. 14.6 Ma.

中文翻译：

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多代理古土壤证据表明雨影效应与北巴塔哥尼亚安第斯山脉中新世隆升有关

近年来，与地形障碍隆起有关的气候变化成为研究热点。为了理解雨影的发展，一些工作着重于气候和构造过程之间的相互作用。巴塔哥尼亚是分析此类相互作用的理想区域，因为中新世气候变化（从潮湿到干燥的条件）主要与安第斯山脉隆升有关。在这项工作中，我们分析了中新世北巴塔哥尼亚前陆盆地中记录的一系列堆积的古土壤，以了解古土壤的水分状况如何与巴塔哥尼亚安第斯山脉隆升引起的大气湿度变化相关。根据宏观，微观和地球化学研究，在基于U-Pb年代学和磁地层学的高分辨率年代地层方案的支持下，古土壤的特征是具有相应的年平均古降水（MAP）和年平均温度值。在前陆填充物（15-14.6 Ma）的底部发现了类似Alfisol的古土壤，其MAP为1229±108 mm / yr。在序列中部（14.6–12.75 Ma）识别的类Andisol类古土壤表现出1053±108 mm / yr的MAP，而在填充物上部（12.75–11.5 Ma）中存在类Aridisol类古土壤。的MAP为677±108毫米/年。确定的中新世年平均温度（〜11±2.1°C）与今天的值（11°C）相似。根据巴塔哥尼亚安第斯山脉的完整构造记录，观测到的MAP下降归因于北巴塔哥尼亚安第斯山脉隆升产生的雨影效应。结果表明，尽管这一过程始于19 Ma左右，但在约20年前，雨影效应并未得到有效记录。14.6马