Abstract Calcretes and palustrine carbonates are two types of continental carbonates that contain significant environmental information and can be found in nearshore environments. In three stratigraphic sections studied in the coastal area of the Yucatan Peninsula and the island of Cozumel, multiple levels of calcretes and palustrine carbonates were identified. The presence of these continental carbonates combined with calcarenites suggests a transition from a shallow marine deposit to a continental environment for paleosol development. This research analyzes the geochemical (δ13C and δ18O), mineralogical and micromorphological characteristics of the calcarenite, palustrine carbonate and calcretes to infer their paleoenvironmental formation conditions. The mineralogy of the samples consists entirely of aragonite and calcite. The micromorphology allowed us to identify α-calcretes and β-calcretes, as well as palustrine carbonates such as peloidal and mottled limestones. The isotopic signature of Palustrine carbonate has an intermediate isotopic signature (δ13C mean value of −5.24‰, δ18O mean value of −4.9‰), falling between that of calcarenites and calcretes. The δ13C (ranging from −10.10 to −7.50‰) and δ18O (−5.63 to −4.64‰) values of all calcretes analyzed in this work are similar to the values reported for the Pleistocene and Holocene calcretes exposed in the Caribbean Sea region. Isotopic values of δ13C in the studied sections are interpreted as the result of a change in vegetation from a predominant C3 vegetation associated with a cool-wet climate to a C3/C4 mixed vegetation, which is a plant cover that grows in a drier-hotter climate.

中文翻译：

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尤卡坦半岛海岸和墨西哥科苏梅尔岛的第四纪碳酸盐岩：古环境影响

摘要 钙质和沼泽碳酸盐是两种大陆碳酸盐岩，它们包含重要的环境信息，可以在近岸环境中找到。在尤卡坦半岛和科苏梅尔岛的沿海地区研究的三个地层剖面中，确定了多层次的钙质和沼泽碳酸盐。这些大陆碳酸盐岩与方解石的存在表明，从浅海沉积物到大陆环境的古土壤发育过渡。本研究分析了方解石、沼泽碳酸盐和钙凝体的地球化学（δ13C 和 δ18O）、矿物学和微形态特征，以推断其古环境形成条件。样品的矿物学完全由文石和方解石组成。微形态使我们能够识别 α-钙质和 β-钙质，以及浅海碳酸盐，如球状和斑驳石灰岩。Palustrine碳酸盐的同位素特征具有中等同位素特征（δ13C平均值为-5.24‰，δ18O平均值为-4.9‰），介于方解石和钙质之间。在这项工作中分析的所有钙质混凝土的 δ13C（范围从 -10.10 到 -7.50‰）和 δ18O（-5.63 到 -4.64‰）值与在加勒比海地区暴露的更新世和全新世钙化物报告的值相似。研究剖面中 δ13C 的同位素值被解释为植被从与凉爽潮湿气候相关的主要 C3 植被转变为 C3/C4 混合植被的结果，后者是一种生长在更干燥、更热的环境中的植物覆盖物。气候。