Abstract Subsurface study of the Palaeozoic deposits in the Chotts basin, part of the southern Tunisian Atlassic foreland, revealed an incomplete Pre-Hercynian deformed sequence. The remaining truncated Cambro-Ordovician siliciclastic deposits appear to be unconformably overlain by transgressive Late Silurian – Early Devonian shales. Early Ordovician El Atchane sandstones and Hamra quartzite constitute currently the most oil and gas productive levels in the Chotts basin. The main issues encountered in the exploration of these reservoirs are related to their spatial distribution along with their thickness and facies variations. Sequence stratigraphic analysis and correlation of the entire Cambro-Ordovician section using sequence stratigraphic surfaces seems necessary to locate both proven and prospective reservoirs in order to predict their spatial distribution and trend directions in the region. Seismostratigraphic facies analysis of these deposits in subsurface highlights their sequence organizations. The integration of well data revealed in detail the sequence hierarchy of the Cambro-Ordovician deposits throughout the Chotts basin.

中文翻译：

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突尼斯南部 Chotts 盆地地下寒武纪硅质碎屑沉积物层序地层：石油意义

摘要 对突尼斯南部阿特拉斯前陆部分 Chotts 盆地中古生代沉积物的地下研究揭示了一个不完整的前海西期变形序列。剩余的截断寒武纪-奥陶纪硅质碎屑沉积物似乎被海侵的晚志留世-早泥盆世页岩不整合覆盖。早奥陶世 El Atchane 砂岩和 Hamra 石英岩构成了目前 Chotts 盆地中油气产量最高的层级。这些储层勘探中遇到的主要问题与其空间分布、厚度和相变化有关。使用层序地层表面对整个寒武系-奥陶系剖面进行层序地层分析和对比，对于定位已证实和潜在储层以预测其在该地区的空间分布和趋势方向似乎是必要的。对这些地下沉积物的地震地层相分析突出了它们的层序组织。井数据的整合详细揭示了整个 Chotts 盆地寒武纪-奥陶纪矿床的层序层次。