Abstract This article presents the results of a research on paleosols formation conditions in the Aguascalientes Valley, northern Mesoamerica, where paleoenvironmental reconstructions have been scarce. Records of environmental and climatic changes, as well as the alteration of the landscape are expressed in the memory of the soil. Soil micromorphology is the most efficient method to identify these changes. In paleosols, micromorphological features reflecting a certain soil forming process can be related to environments in which those processes took place. Paleoenvironmental reconstruction of the region consisted in identifying pedofeatures and other present soil attributes, grouping features into pedogenic facies under constant environmental conditions, examining the groundmass in order to detect features caused by erosion or sedimentation, and finally establishing a hierarchy between the different pedogenic facies, including erosional and sedimentary features if necessary. Specific statistical data analysis disclosed stratigraphical relationships. The results we obtained, such as illuvial clay coatings, redoximorphic nodules, and hypocoatings, revealed the most representative pedofeatures that developed under humid climate. Under a semiarid climate, representative pedofeatures that were revealed included micritic coatings and hypocoatings. A paleosol with ferruginous nodules and hypocoatings in groundmass, and at least one phase of dusty and high-birefringence yellow clay illuviation is proposed as stratigraphic marker for this area of the Aguascalientes Valley. Evidence indicates the sequence of events in the area was: (i) a large period of humid climate; (ii) a short period of climate change, from humid to semiarid, followed by subhumid; and (iii) a large period of semiarid climate, including the current one. The paleosols of the Aguascalientes Valley to a large extent preserve major trends in history and provide further evidence to define the 11 phases of stability (pedogenesis) in 8 cycles and to detect the interlayer phases of instability (sediment transport/deposition).

中文翻译：

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中美洲北部未公开的古气候记录：环境重建的地层学方法

摘要 本文介绍了中美洲北部阿瓜斯卡连特斯山谷古土壤形成条件的研究结果，该地区的古环境重建很少。环境和气候变化的记录，以及景观的改变，都在土壤的记忆中表达出来。土壤微形态学是识别这些变化的最有效方法。在古土壤中，反映特定土壤形成过程的微形态特征可能与这些过程发生的环境有关。该地区的古环境重建包括识别土壤特征和其他现有土壤属性，在恒定环境条件下将特征分组为成土相，检查地块以检测由侵蚀或沉积引起的特征，最后在不同的成土相之间建立层次结构，必要时包括侵蚀和沉积特征。具体的统计数据分析揭示了地层关系。我们获得的结果，如沉积粘土涂层、氧化还原结节和低涂层，揭示了在潮湿气候下形成的最具代表性的土壤特征。在半干旱气候下，显示的代表性土壤特征包括泥晶涂层和低涂层。在地块中具有铁质结核和底涂层的古土壤，以及至少一个尘土和高双折射黄色粘土沉积相被提议作为阿瓜斯卡连特斯山谷这一地区的地层标记。有证据表明，该地区的一系列事件是：(i) 一个大时期的潮湿气候；(ii) 短期气候变化，从湿润到半干旱，然后是半湿润；(iii) 很长一段时间的半干旱气候，包括目前的气候。阿瓜斯卡连特斯山谷的古土壤在很大程度上保留了历史上的主要趋势，并为定义 8 个循环中的 11 个稳定阶段（成土作用）和检测不稳定的层间阶段（沉积物运输/沉积）提供了进一步的证据。