Inversion tectonics at the northern margin of the North German Basin: Cretaceous to recent reactivation of Triassic normal faults (iTec-NGB)

北德盆地北缘的反转构造：白垩纪到三叠纪正断层的近期重新活动（iTec-NGB）

• 批准号: 465329435
• 负责人: Professor Dr. Christian Hübscher
• 金额: --
• 依托单位: Institut for Geoscience
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2021
• 资助国家: 德国
• 起止时间: 2020-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/465329435?language=en
• 关键词: Inversion; tectonics; northern; margin; North

Near-surface faults within late Pleistocene, possibly Holocene strata are located in the eastern prolongation of a west-east striking graben across Langeland Island (Danish sector of the Baltic Sea) and correlate with deep-rooted faults within Triassic and Cretaceous strata. These faults are located above a prominent basement horst structure of the Ringkøbing-Fyn High, which marks the northern margin of the North German Basin (NGB). This project strives for investigating the tectonic evolution of the northern NGB margin east of Langeland Island and its relation to the post-Permian to recent evolution of the NGB by means of seismic interpretation. The study area allows investigating the early phases of basin formation dominated by extension and corresponding development of basin margin normal faults during the Triassic, their compressional reactivation as reverse faults during Late Cretaceous and Cenozoic basin inversion, and possible recent tectonic movements as well as post-glacial isostatic adjustments. In 2020, 27 high-resolution multi-channel reflection seismic and parametric echosounder profiles have been collected east of Langeland. To reveal the complex multiphase evolution of the northern NGB margin, these data have to be processed, interpreted and discussed within the tectonic framework. A first data example indicates the reactivation of normal faults, bounding tilted Triassic blocks, as reverse faults that uplifted overlying Cretaceous strata and pierce into overlying Pleistocene units. However, the exact outline of the fault system remains unknown. Incorporating more seismic data into the interpretation will improve the understanding of fault system evolution and reveal its exact outline and connection to deep-seated structures of the Ringkøbing-Fyn High. The quantitative analysis of fault displacement requires seismic depth sections obtained by high-quality velocity models. Migration velocity model building will be achieved by using an innovative processing flow based on a diffraction extraction technique. This technique uses diffraction wavefront attributes to calculate lateral variable velocity information even for short-offset seismic data. Additionally, extracted diffractions will help to identify faults and improve the understanding of the fault system and its geometry. Growth faulting visible in the produced depth sections will allow quantification of active phases of tectonic movement, which will be discussed in the context of the known phases of basin subsidence and inversion from other areas of the NGB and adjacent sub-basins of the Central European Basin System.

在更新世晚期的近地面断层，可能的全新世施特拉（Wol Cencene Straa）位于兰格兰岛（Langeland Island）（波罗的海丹麦地区）的东方醒目的东部延长中，并与三叠纪和白垩纪阶层的深层断层相关。这些断层位于Ringkøbing-Fyn High的著名地下马结构上方，标志着北德盆地（NGB）的北边缘。该项目致力于调查兰格兰岛以东的北NGB边缘的构造演化，并通过地震解释来调查兰格兰岛以东的北部NGB边际及其与佩尔mian近期NGB进化的关系。该研究区域允许研究三叠纪期间盆地形成的早期阶段，并以扩展和相应的发展为主，其压缩重新激活为正常的断层在白垩纪晚期和新生代盆地倒置期间的反向断层，以及最近可能的构造运动，以及几乎没有的构造运动以及几路后的等距性相位量表调节。在2020年，已收集了兰格兰（Langeland）的27种高分辨率多通道反射地震和参数回声器曲线。为了揭示北部NGB边缘的复杂多相演化，必须在构造框架中处理，解释和讨论这些数据。第一个数据示例表明正常断层的重新激活，边界倾斜的三叠纪块，是反向断层，使上覆的白垩纪stra升高并刺穿到上层更新世单元中。但是，断层系统的确切轮廓仍然未知。将更多的地震数据纳入解释将改善对断层系统演变的理解，并揭示其与Ringkøbing-Fyn高中深处结构的确切轮廓和联系。断层位移的定量分析需要高质量速度模型获得的地震深度部分。通过使用基于衍射提取技术的创新处理流量来实现迁移速度模型构建。该技术使用衍射波前属性来计算横向可变速度信息，即使对于短偏移地震数据也是如此。此外，提取的衍射将有助于识别故障并改善对断层系统及其几何形状的理解。生长断层在产生的深度部分中可见，将允许量化构造运动的活动阶段，这将在盆地沉降的已知阶段进行讨论，并从NGB的其他地区和中欧盆地中部的邻近子基础上进行反转。