Basin evolution and deposition during the Early Paleogene in Tunisia
Basin evolution and deposition during the Early Paleogene in Tunisia
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突尼斯早古近纪盆地演化与沉积
DOI：
10.1144/gsl.sp.1998.132.01.21
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
R. Moody
中科院分区：
文献类型：
--
作者：
A. Zaïer;A. Beji;S. Sassi;R. Moody
突尼斯的El哈里亚组和梅特拉维组中的海相古新世和伊普雷期沉积物由于对磷酸盐和碳氢化合物的商业兴趣而得到了深入的研究。本文介绍了最新更新的等时线图、岩相图和古地理图，并根据同沉积构造解释了所识别的模式。这揭示了构造、盆地几何形状和沉降之间的密切联系。古近纪早期沉积相分布受沿着基底线性构造控制。这些主要的断层系统在中生代和第三纪被重新激活了几次，最后的运动发生在新近纪和后Villafranchian事件。构造控制相是最明显的在伊普雷期，特别是沿着“南北轴”（Nosa）的亚子午线造山段突尼斯中部。在这一地区，伊普雷期沉积物表现出与诺萨的优先对齐，对盆地几何形状和局部沉降率产生显着影响。除了在突尼斯的陆上地区指出的两个大岛外，在近海还发现了一些“秃”高点，代表原始的海底高点。在整个时期，突尼斯的总体格局是一些小的构造控制盆地。磷块岩、富含有机物的页岩和碳酸盐岩的分布与这一时期限制性盆地的发育密切相关。
Abstract The marine Paleocene and Ypresian deposits of Tunisia, within the El Haria Formation and the Metlaoui Group, have been intensively studied because of the commercial interest in phosphates and hydrocarbons. This paper presents the latest updates of isochron, lithofacies and palaeogeographical maps, and interprets the patterns identified in light of synsedimentary structure. This reveals a close association between structure, basin geometry and subsidence. Facies distribution during the Early Paleogene is thought to be structurally controlled along basement lineaments. These major fault systems were reactivated several times during the Mesozoic and Tertiary, with the last movements occurring as Neogene and post-Villafranchian events. The structural control of facies is most evident during the Ypresian, particularly along the ‘North-South Axis’ (Nosa) a sub-meridian orogenic segment of Central Tunisia. In this area the Ypresian deposits exhibit a preferred alignment with the Nosa exerting a notable influence on basin geometries and rates of local subsidence. In addition to two large islands indicated in the onshore area of Tunisia, a number of ‘bald’ highs are identified in the offshore, representing original submarine highs. The general pattern across Tunisia throughout the period is of a number of small tectonically controlled basins. The distribution of phosphorites, organic-rich shales and evaporites can be particularly linked to the development of restricted basins during the period.