Active tectonics in the Upper Rhine Graben Integration of paleoseismology, geomorphology and geomechanical modeling
Active tectonics in the Upper Rhine Graben Integration of paleoseismology, geomorphology and geomechanical modeling
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莱茵河上游地堑的活动构造古地震学、地貌学和地质力学建模的整合
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发表时间：
2007
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通讯作者：
G. Peters
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作者：
G. Peters
本文以上莱茵地堑北部为研究对象。本文的目的是研究该地区第四纪和现世的活动构造。URG具有人为活动剧烈，构造变形相对缓慢，板块内地震活动较低的特点。此外，在第四纪期间，地表过程一直以较高的速率进行。因此，缓慢构造变形的记录保存相对较差，难以探测。在这样的背景下，需要运用多种技术来研究活动构造。本文认为，综合运用古地震沟探、河流阶地填图、定量构造地貌和构造模拟四种技术，可以取得积极的成果。本文第一章综述了塔里木盆地的地球动力学演化、构造背景和地震活动性。第二章介绍并讨论了古地震沟的结果，包括浅层地球物理测量结果。本次调查的重点是URG北部的西部边界断层（WBF）。这些沟暴露了中晚更新世沉积（河流砂、冲积性黄土）中边界断裂的近地表变形。由于不可能对该地点的同震变形提供明确的证据，因此提出了两种情况：一次6.5级地震或以0.04毫米/年的速度发生地震蠕变。利用14C和热释光测年，确定了该断裂带的最后一次断裂期为8 ~ 19 ka。通过对事件序列的重建，可以证明西北缘的构造活动与海沟部位的河流和侵蚀过程之间的相互作用。在区域尺度上，研究了断层活动对河流阶地的影响（第3章）。这项工作包括沿WBF段进行沟槽调查的形态阶地测绘。将这些新绘制的梯田与之前沿着URG北部西侧绘制的梯田进行对比，可以得出XV
In the focus of this thesis is the northern part of the Upper Rhine Graben (URG). The aim of the thesis is to study the active tectonics of the area during the Quaternary and Present. The URG is characterized by intense human modifications, relatively slow tectonic deformation and low intra-plate seismic activity. In addition, during the Quaternary surface processes have been at a high rate. Therefore, the records of the slow tectonic deformation are relatively poorly preserved and thus difficult to detect. Given this setting, several techniques need to be applied in order to study the active tectonics. This thesis demonstrates that the integration of four techniques, paleoseismological trenching, fluvial terrace mapping, quantitative tectonic geomorphology and tectonic modeling, can lead to positive results. Chapter 1 of this thesis presents a review of the geodynamic evolution, the structural setting and the seismicity of the URG. The results of paleoseismological trenching, including shallow geophysical measurements, are presented and discussed in Chapter 2. This investigation focuses on the Western Border Fault (WBF) in the northern URG. The trenches exposed near-surface deformation of the border fault in Middle to Late Pleistocene deposits (fluvial sands, alluvial loess). Since unambiguous proof for co-seismic deformation is not possible for this site two scenarios are proposed: a single M w 6.5 earthquake or aseismic creep at a rate of > 0.04 mm/yr. Using 14C and thermoluminescence dating the last faulting episode of the WBF at this site was dated between 8 and 19 ka. Based on a reconstruction of the sequence of events, the interplay between tectonic activity of the WBF and fluvial and erosional processes at the trench site could be demonstrated. At a regional scale, the effects of fault activity on fluvial terraces are investigated (Chapter 3). The work includes morphological terrace mapping along the WBF segment investigated by trenching. Correlation of these newly mapped terraces with previous terrace mapping along the western side of the northern URG permits XV