Abstract

Tunisia had been the place of various tectonic episodes which have drawn the actual structural map of the country. The Neogene period was the most active period in which the collision contributed to the mountain ranges formation such as the Atlassic chain. The contrast of mechanical behavior between the different sedimentary units of the cover and the substratum is a determining factor that has controlled the deformation style of many folding structures. Detachment folding has been studied on the basis of field and seismic data examples from the Northeastern Tunisia. We discuss different aspects of detachment to constrain the chronology of structural events and understand the cover‒substratum relationship during the major folding phases. In the present paper, we found that the deformation style admitted previously do not reflect adequately the tectonic structure of Kechabta Neogene basin (North of Tunisia). The cover-substratum relationship study at this area revealed two major shortening phases; the first had been happened during the Upper Tortonian and the second in the Lower Quaternary. The resulting folding style is characterized by disharmonic and multi-layers detachment phenomena produced by incompetent evaporitic sequences. The two described folding phases are superimposed and testify at a large scale the continental collision which controls the North African margin during the Late Miocene to the Quaternary.

中文翻译：

---

突尼斯东北部冰河流域的同碰撞折叠和多层拆离

摘要

突尼斯曾是各种构造事件的发源地，绘制了该国的实际结构图。新近纪是最活跃的时期，在这一时期中碰撞促成了诸如Atlassic链之类的山脉形成。覆盖物和基底的不同沉积单元之间的机械行为的对比是决定了许多折叠结构变形样式的决定因素。已经根据突尼斯东北部的实地和地震数据实例研究了拆离折叠。我们讨论了分离的不同方面，以约束结构事件的时间顺序，并了解主要折叠阶段中盖层与底层之间的关系。在本文中，我们发现，先前承认的变形方式不能充分反映凯沙布塔新近纪盆地（突尼斯北部）的构造构造。在该区域的覆盖层-底层关系研究显示出两个主要的缩短阶段：第一次发生在上托托期，第二次发生在下第四纪。产生的折叠样式的特征是由不适当的蒸发序列产生的不和谐和多层分离现象。所描述的两个折叠阶段是重叠的，并在很大程度上证明了中新世晚期至第四纪期间控制北非边缘的大陆碰撞。第一次发生在上托托期，第二次发生在下第四纪。产生的折叠样式的特征是由不适当的蒸发序列产生的不和谐和多层分离现象。所描述的两个折叠阶段是重叠的，并在很大程度上证明了中新世晚期至第四纪期间控制北非边缘的大陆碰撞。第一次发生在上托托期，第二次发生在下第四纪。产生的折叠样式的特征是由不适当的蒸发序列产生的不和谐和多层分离现象。所描述的两个折叠阶段是重叠的，并在很大程度上证明了中新世晚期至第四纪期间控制北非边缘的大陆碰撞。