The exceptionally glauconite-rich Miocene strata, superbly exposed throughout the front of the nappes zone of northern Tunisia, show marked contrast in Fe-silicate authigenesis within and outside foraminifera chambers. Glauconite forms by the alteration of fecal pellet, quartz, feldspar, volcaniclastic particles, feldspar, and quartz. X-ray diffraction patterns show the characteristic peaks of the ‘evolved’ variety glauconite. The glauconite contains high K₂O and Al₂O₃ and moderate to high Fe₂O₃ (total). While chamosite occurs solely as infillings within bioclasts pores, containing high Fe₂O₃ and Al₂O₃. Each of the glauconitic intervals coincide with the peak rise of third order sea-level cycles during the Burdigalian-Langhian time. Glauconite occurs at the base of coarsening- and thickening-upward hemicycles consisting of shale and sandstone, recording a shallowing upward trend across offshore-shoreface settings. The glauconitic parasequences are correlated across the Tethyan margin. Within the Miocene succession of Tunisia, glauconite formed on shallow marine dysoxic bottom water condition charged with abundant cations. On the other hand, anoxic micro-environment within the bioclasts pore spaces, induced by the decomposition of organic matter, favored the fixation of Fe²⁺ into the crystal structure, forming chamosite. Contemporaneous volcanism in Algeria and surrounding areas, in response to the African-European plate convergence, appears to be the most significant sources of Fe and other cations necessary for green clay authigenesis. Therefore, the occurrence of glauconite in the Miocene succession of Tunisia, is influenced by the combination of eustacy and volcanism, the type of substrate dictating the ultimate composition of the authigenic Fe-silicates.

异常富含海绿石的中新世地层，在突尼斯北部推覆带的整个前部极好地暴露，在有孔虫室内外的铁硅酸盐自生中显示出明显的对比。海绿石由粪便、石英、长石、火山碎屑颗粒、长石和石英的蚀变形成。X 射线衍射图显示了“进化”品种海绿石的特征峰。海绿石含有高K ₂ O 和Al ₂ O ₃以及中等至高Fe ₂ O ₃ (总量)。菱铁矿仅作为生物碎屑孔隙内的填充物出现，含有高 Fe ₂ O₃和 Al ₂ O ₃ 。在布尔迪加利安-朗吉安时期，每个青海岩层段都与三阶海平面循环的峰值上升相吻合。海绿石出现在由页岩和砂岩组成的粗化和增厚的向上半旋回的底部，记录了整个近海岸面环境的变浅上升趋势。整个特提斯边缘的青光石副层序是相关的。在突尼斯的中新世序列中，海绿石形成于浅海缺氧底水条件下，其中含有丰富的阳离子。另一方面，由有机物分解引起的生物碎屑孔隙空间内的缺氧微环境有利于 Fe ²⁺的固定。进入晶体结构，形成菱镁矿。阿尔及利亚及周边地区的同期火山活动，响应非洲-欧洲板块的汇聚，似乎是绿粘土自生所必需的 Fe 和其他阳离子的最重要来源。因此，突尼斯中新世序列中海绿石的出现受洋洋性和火山作用的组合影响，底物类型决定了自生铁硅酸盐的最终组成。