Pedogenic carbonates are considered important indicators of past climatic changes. Their formation is due to calcite accumulation through evaporation processes in arid or semi-arid regions. Over time, secondary carbonate accumulation results in the development of calcic and petrocalcic horizons in soil profiles. In this study, we conducted an analysis of pedogenic carbonates as records of paleoenvironmental characteristics in the Teotihuacan Valley, Basin of Mexico. Micromorphological, mineralogical, and geochemical characteristics of secondary carbonates from three paleosol profiles (Cerro Gordo 1, Cerro Gordo 2, and Maseca 1) were analyzed. Pedogenic carbonates were characterized by irregular and variable carbonate crystal sizes, inclusions of soil particles, and dark or light micrite and microsparite laminations. Micromorphology and scanning electron microscopy revealed weathered plagioclase minerals as a potential source of calcium for carbonate precipitation. The ⁸⁷Sr/⁸⁶Sr ratio of carbonate laminar crusts and nodules from the analyses pedons in the study area also indicated that rocks of the Transmexican Volcanic Belt were the principal source of Ca and Sr for carbonates, while contribution of a far-distance eolian input was minimal. The δ¹³C isotopic composition evidenced a mixture of C3 and C4 plants during the Pleistocene and a transition to a higher proportion of C4 vegetal cover during the Holocene. This agreed with an increase in modeled paleo-temperature from 10.9 °C to 13.7 °C based on ¹⁸O-temperature equations. Our results support those determined for the regional paleoenvironment during the Pleistocene, the Pleistocene-Holocene transition and Mid-Late Holocene.

成土碳酸盐被认为是过去气候变化的重要指标。它们的形成是由于方解石通过干旱或半干旱地区的蒸发过程积累。随着时间的推移，二次碳酸盐的积累导致土壤剖面中钙和岩钙层的发展。在这项研究中，我们对成土碳酸盐进行了分析，作为墨西哥盆地特奥蒂瓦坎谷古环境特征的记录。分析了三个古土壤剖面（Cerro Gordo 1、Cerro Gordo 2 和 Maseca 1）中次生碳酸盐的微形态、矿物学和地球化学特征。成土碳酸盐的特征是不规则和可变的碳酸盐晶体尺寸、土壤颗粒的内含物以及深色或浅色泥晶和微细晶层。微观形态学和扫描电子显微镜显示风化斜长石矿物是碳酸盐沉淀的潜在钙源。这^{研究区分析地层的碳酸盐层状结壳和结核的87} Sr/ ⁸⁶ Sr 比值也表明，横贯墨西哥火山带的岩石是碳酸盐岩 Ca 和 Sr 的主要来源，而远距离风成输入的贡献是最小。δ ¹³ C 同位素组成证明了更新世期间 C3 和 C4 植物的混合物以及全新世期间向更高比例的 C4 植物覆盖的过渡。^{这与基于18 个}O 温度方程的模拟古温度从 10.9 °C 增加到 13.7 °C 一致。我们的结果支持更新世、更新世-全新世过渡和全新世中晚期区域古环境的确定。