Lithofacies analyses were undertaken on a suite of well-exposed carbonate deposits from the (Pliocene) Mayrán Formation, in the Mayrán Basin system, northeast Mexico to investigate the controls on carbonate lithofacies variability in a series of linked lacustrine subbasins, with a common hydrology yet very different inputs.

The lacustrine carbonates contain variable proportions of production-derived components, with subordinate proportions of detrital and early diagenetic components. The lithofacies contain, inorganic and organic calcite (average 91% CaCO₃), and organic matter (10.5%–13.8% average 12.6% TOC), together with minor detrital minerals. Nine sub-facies were identified: ostracod mudstone-wackestone, clotted boundstones, gastropod wackestone-packstones, oncoid wackestone-packstones, charophyte wackestone-packstones, crystalline carbonate mudstone, stromatolites, crystalline carbonate, marlstone, and associated evaporite minerals. Isotopic composition of specific components such as micritic laminations in stromatolites (δ¹³C_calcite −6.3‰ and δ¹⁸O_calcite −8.0‰), and micrititic matrix from samples in all the subbasins (δ¹³C_calcite −5.7‰ and δ¹⁸O_calcite −7.8‰), indicate that overall calcite deposition occurred in freshwater lakes. Non luminescent (e.g. charophytes) to orange dull luminescencent micrite strongly suggest in situ carbonate production. Together these processes contributed to the local production of lime mud. Additionally, microtextural evidence of scour surfaces however, indicates that occasionally the sediment was reworked and transported laterally and basinward. Fossil content and diversity composed by Limnaeidae, Physidae, and Planorbidae types, together with phosphatised bone fragments, micro-oncoids, stromatolites, microbial morphotypes, charophytes, macrophyte phytoherms, and microcodium structres, are good references for lithofacies characterization and indicators of specific paleoenvironmental conditions. Intense to moderate bioturbation (BI 1 to 4), indicates that deposition took place under predominantly oxic conditions. Significant organic matter was preserved in these lacustrine rocks, likely controlled by moderate rates of carbonate mud production.

The lacustrine lithofacies were deposited in proximal and distal lacustrine settings, making possible to recognize basin scale variability. Strata staking patterns are organized into shallowing upwards cycles (0.3–2.5 m thick), which are capped either by evaporites or beds with a pedogenic overprint. Their stacking patterns reflect lake level variations which can be recognized in all the subbasins. The lithofacies architecture within each subbasin forms parasequences that overall exhibit aggradational geometries. The lithofacies and their large scale geometries also indicate deposition occurred in a series of relatively shallow (<10 m), lake systems with ramp-like margins. The aggradational stacking patterns of the carbonates and the presence of subordinate evaporites suggest that basin hydrology (water supply and precipitation/evaporation ratios) had an important influence on facies architecture and cyclicity. The Mayrán Formation lacustrine lithofacies deposited under overfilled to balance-filled lake conditions; although balance-filled conditions with an open hydrology were more likely.

Overall, facies variability in the lacustrine carbonate lithofacies was controlled by basin inherited geomorphology, accommodation, and basin hydrology, which ultimately controlled clastic trapping, solute inputs, water chemistry, primary production, and lake level changes. We interpret that all these controls were largely driven by climate.

对墨西哥东北部迈兰盆地系统（上新世）迈兰组的一组出露良好的碳酸盐沉积物进行了岩相分析，以研究对一系列相连的湖相亚盆地中碳酸盐岩相变异性的控制，但具有共同的水文非常不同的输入。

湖相碳酸盐岩含有不同比例的生产衍生成分，次要比例的碎屑和早期成岩成分。岩相包含无机和有机方解石（平均 91% CaCO ₃）和有机质（10.5%–13.8% 平均 12.6% TOC），以及少量碎屑矿物。确定了九个亚相：介形泥岩-泥质岩、凝块状边界岩、腹足类泥质-泥质岩、轮状泥质-泥质岩、轮藻-泥质-泥质、结晶碳酸盐泥岩、叠层石、结晶碳酸盐、泥灰岩和伴生蒸发岩矿物。特定成分的同位素组成，例如叠层石中的泥晶层理（δ ¹³ C_方解石-6.3‰ 和 δ ¹⁸O_方解石-8.0‰)和所有子流域样品的泥质岩基质(δ ¹³ C_方解石-5.7‰和δ ¹⁸ O_方解石-7.8‰)表明，方解石总体沉积发生在淡水湖泊中。不发光（例如轮藻）到橙色暗淡发光泥晶强烈建议原位碳酸盐生产。这些过程共同促成了当地石灰泥的生产。此外，冲刷表面的微观结构证据表明，沉积物偶尔会被重新加工并横向和向盆地输送。由 Limnaeidae、Physidae 和 Planorbidae 类型组成的化石含量和多样性，连同磷化骨碎片、微核石块、叠层石、微生物形态类型、轮藻、大型植物群和微核结构，是岩相特征和特定古环境条件的良好参考. 强烈到中度的生物扰动（BI 1 到 4）表明沉积发生在主要有氧条件下。这些湖相岩石中保存了大量有机质，

湖相岩相沉积在近端和远端湖相环境中，使得识别盆地尺度变化成为可能。地层放样模式被组织成向上变浅的循环（0.3-2.5 m 厚），被蒸发岩或带有成土覆盖的床覆盖。它们的堆积模式反映了在所有子流域中都可以识别的湖水位变化。每个子盆地内的岩相结构形成副层序，总体上表现出聚集的几何形状。岩相及其大尺度几何形状也表明沉积发生在一系列相对浅（<10 m）、具有斜坡状边缘的湖泊系统中。碳酸盐岩的堆积堆积模式和次级蒸发岩的存在表明盆地水文（供水和降水/蒸发比）对相结构和旋回性有重要影响。Mayrán 组湖相岩相在过度充填到平衡充填的湖泊条件下沉积；尽管具有开放水文的平衡条件更有可能发生。

总体而言，湖相碳酸盐岩相的变化受盆地继承地貌、容纳和盆地水文控制，最终控制碎屑圈闭、溶质输入、水化学、初级生产和湖泊水位变化。我们解释说，所有这些控制主要是由气候驱动的。