Tectonic evolution of the South Atlantic passive continental margin based on onshore structural data

这项工作将涉及南大西洋的开放及其边缘的构造发展，特别强调巴西的Parána LIP（大火成岩省）和纳米比亚的Etendeka LIP。我们将研究深部地幔过程、远场板块应力和局部边缘动力学对被动边缘的影响。我们的第一个假设是，南大西洋两侧的边缘经历了一个非常不同的发展后，LIP挤压，因为热点活动的两个边缘不同，巴西的边缘是由安第斯山脉（目前正在压缩在E-W方向）的影响。我们的第二个假设认为，被动大陆边缘沿大弗洛里亚诺波利斯/格兰德河断裂带和相关断层向岸沿着分段，并随时间经历不同的块体运动。第二个假设是基于新的热年代学数据组装在第一个采样阶段，这表明边缘分割。我们的第三个假设是，复活的基底断裂边缘动力学中起着重要的作用。Parána和Etendeka LIP'S及其与基底岩石的接触是边缘裂谷后发展的理想档案。对基底断层的重新活动进行详细的实地工作后，将进行断层滑动分析，以确定当地的古应力状态（主应力方向和差应力的相对比率）。我们将使用一种新的强大的方法（SVS方法，Sippel et al. 2009），使我们能够分离不同的压力状态，并彻底测试它们。最后，我们将尝试使用相对断层交叉点，断层岩脉关系，在那里我们将从附带的项目中获得重要的火山岩和热年代学数据，以适应时间框架中确定的应力状态。我们的目标是产生一个新的tectonicthermochronologic模型的动力学的南大西洋边缘，他们的差异和分割。我们的工作解决了重要的SAMPLE问题，将与海上研究进行比较和调整，并为大规模数值模型建立理想的基础。

This work will deal with the opening of the South Atlantic and the tectonic development of its margins with special emphasis on the Parána LIP’s (Large Igneous Province) in Brazil and the Etendeka LIP’s in Namibia. We will study the effects of deep-seated mantle processes, far-field plate stresses and local margin dynamics on the passive margin. Our first hypothesis is that the margins on both sides of the South Atlantic experienced a very different development following LIP extrusion, since hot-spot activities on both margins vary and the Brazilian margin is influenced by the Andean orogeny (being currently under compression in an E-W direction). Our second hypothesis states that the passive continental margin is segmented onshore along the large Florianopolis/Rio Grande Fracture Zone and associated faults and experiences different block movements through time. The second hypothesis is based on new thermochronologic data assembled in the first SAMPLE phase, which shows margin segmentation. Our third hypothesis is that reactivation of basement faults plays an important role in the margin dynamics. The Parána and Etendeka LIP’S and their contact to the basement rocks are an ideal archive of the post-rift development of the margin. Detailed field-work on reactivation of basement faults will be followed by a fault slip analysis in order to determine local paleo-stress states (directions of principal stresses and relative ratios of differential stresses). We will use a new powerful method (SVS-method, Sippel et al. 2009) that allows us to separate different stress states and test them thoroughly. Finally we will try to fit the determined stress states in time frames using relative fault intersections, fault dyke relations where we will date important volcanics and thermochronological data from the accompanying project. We aim to produce a new tectonicthermochronologic model of the dynamics of the South Atlantic margins, their differences and segmentation. Our work tackles important SAMPLE questions, will be compared and adjusted to offshore studies and builds an ideal basis for large-scale numerical models.