The late Aptian Lower Serdj Formation (LSF) in the Northern Atlas of Tunisia records a mixed carbonate–siliciclastic system from the southern margin of Tethys. Sedimentological investigations of key sections in the Serdj-Bargou area along a NE–SW-platform-to-basin profile reveal five shallow-marine carbonate units (Cu1, Cu2, Cu3, Cu4a and Cu4b), dominated by subtidal deposits, separated by four terrigenous units (T1, T2, T3, T3a). Twelve basic facies are grouped into six facies associations or zones (FZA to FZF), representing particular palaeo-environments from proximal to distal settings. Carbonate units Cu1, Cu2 and Cu4a are dominated by coral algal-Orbitolina facies representative of a homoclinal ramp. However, units Cu3 and Cu4b are dominated by high-energy oolitic facies of a shoaled ramp. The terrigenous deposits (T1 to T4) are dominated by siliciclastics with shale, sandstone/siltstone and marl and have mostly been assigned to off-platform to basinal environments (FZF). The vertical facies changes are closely related to amplitudes of sea-level fluctuations and late Aptian Tethyan climatic perturbations. The terrigenous units were the result of short cooling periods and a humid climate. Moreover, this climate favoured the development of tide-influenced oolitic shoals, with the nuclei of ooids formed by fine quartz grains. Both the oolitic and siliciclastic deposits reflect episodes of maximum platform progradation basin-ward at a time of low accommodation space through the late Aptian period. Overall the new stratigraphic dataset from the southern Tethys margin is interpreted as reflecting the global Late Aptian cooling episode and sea-level lowstand.

突尼斯北部阿特拉斯的晚期 Aptian 下 Serdj 组 (LSF) 记录了特提斯南缘的混合碳酸盐-硅质碎屑系统。对 Serdj-Bargou 地区沿 NE-SW 台地-盆地剖面的关键剖面进行的沉积学调查揭示了 5 个浅海碳酸盐单元（Cu1、Cu2、Cu3、Cu4a 和 Cu4b），以潮下沉积物为主，由四个单元分隔开陆源单位（T1、T2、T3、T3a）。十二个基本相分为六个相组合或区域（FZA 至 FZF），代表从近端到远端的特定古环境。碳酸盐单元 Cu1、Cu2 和 Cu4a以代表同斜斜坡的珊瑚藻-Orbitolina相为主。然而，Cu3 和 Cu4b 单元以浅滩斜坡的高能鲕岩相为主。陆源矿床（T1 至 T4）以硅质碎屑岩、页岩、砂岩/粉砂岩和泥灰岩为主，大部分属于台外盆地环境 (FZF)。垂向相变化与海平面波动幅度和特提斯晚期气候扰动密切相关。陆源单位是短暂冷却期和潮湿气候的结果。此外，这种气候有利于受潮汐影响的鲕粒滩的发育，鲕粒岩的核由细小的石英颗粒形成。鲕粒岩和硅碎屑沉积物都反映了阿普第晚期在可容纳空间较低的时期向盆地方向最大台地进积的时期。总体而言，来自特提斯南缘的新地层数据集被解释为反映了全球晚阿普第期冷却事件和海平面低位。